Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
authorLinus Torvalds <torvalds@linux-foundation.org>
Fri, 19 Mar 2021 21:10:07 +0000 (14:10 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 19 Mar 2021 21:10:07 +0000 (14:10 -0700)
Pull kvm fixes from Paolo Bonzini:
 "Fixes for kvm on x86:

   - new selftests

   - fixes for migration with HyperV re-enlightenment enabled

   - fix RCU/SRCU usage

   - fixes for local_irq_restore misuse false positive"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  documentation/kvm: additional explanations on KVM_SET_BOOT_CPU_ID
  x86/kvm: Fix broken irq restoration in kvm_wait
  KVM: X86: Fix missing local pCPU when executing wbinvd on all dirty pCPUs
  KVM: x86: Protect userspace MSR filter with SRCU, and set atomically-ish
  selftests: kvm: add set_boot_cpu_id test
  selftests: kvm: add _vm_ioctl
  selftests: kvm: add get_msr_index_features
  selftests: kvm: Add basic Hyper-V clocksources tests
  KVM: x86: hyper-v: Don't touch TSC page values when guest opted for re-enlightenment
  KVM: x86: hyper-v: Track Hyper-V TSC page status
  KVM: x86: hyper-v: Prevent using not-yet-updated TSC page by secondary CPUs
  KVM: x86: hyper-v: Limit guest to writing zero to HV_X64_MSR_TSC_EMULATION_STATUS
  KVM: x86/mmu: Store the address space ID in the TDP iterator
  KVM: x86/mmu: Factor out tdp_iter_return_to_root
  KVM: x86/mmu: Fix RCU usage when atomically zapping SPTEs
  KVM: x86/mmu: Fix RCU usage in handle_removed_tdp_mmu_page

18 files changed:
Documentation/virt/kvm/api.rst
arch/x86/include/asm/kvm_host.h
arch/x86/kernel/kvm.c
arch/x86/kvm/hyperv.c
arch/x86/kvm/hyperv.h
arch/x86/kvm/mmu/mmu_internal.h
arch/x86/kvm/mmu/tdp_iter.c
arch/x86/kvm/mmu/tdp_iter.h
arch/x86/kvm/mmu/tdp_mmu.c
arch/x86/kvm/x86.c
tools/testing/selftests/kvm/.gitignore
tools/testing/selftests/kvm/Makefile
tools/testing/selftests/kvm/include/kvm_util.h
tools/testing/selftests/kvm/lib/kvm_util.c
tools/testing/selftests/kvm/lib/kvm_util_internal.h
tools/testing/selftests/kvm/x86_64/get_msr_index_features.c [new file with mode: 0644]
tools/testing/selftests/kvm/x86_64/hyperv_clock.c [new file with mode: 0644]
tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c [new file with mode: 0644]

index 38e327d..307f2fc 100644 (file)
@@ -1495,7 +1495,8 @@ Fails if any VCPU has already been created.
 
 Define which vcpu is the Bootstrap Processor (BSP).  Values are the same
 as the vcpu id in KVM_CREATE_VCPU.  If this ioctl is not called, the default
-is vcpu 0.
+is vcpu 0. This ioctl has to be called before vcpu creation,
+otherwise it will return EBUSY error.
 
 
 4.42 KVM_GET_XSAVE
@@ -4806,8 +4807,10 @@ If an MSR access is not permitted through the filtering, it generates a
 allows user space to deflect and potentially handle various MSR accesses
 into user space.
 
-If a vCPU is in running state while this ioctl is invoked, the vCPU may
-experience inconsistent filtering behavior on MSR accesses.
+Note, invoking this ioctl with a vCPU is running is inherently racy.  However,
+KVM does guarantee that vCPUs will see either the previous filter or the new
+filter, e.g. MSRs with identical settings in both the old and new filter will
+have deterministic behavior.
 
 4.127 KVM_XEN_HVM_SET_ATTR
 --------------------------
index 9bc091e..3768819 100644 (file)
@@ -884,12 +884,29 @@ struct kvm_hv_syndbg {
        u64 options;
 };
 
+/* Current state of Hyper-V TSC page clocksource */
+enum hv_tsc_page_status {
+       /* TSC page was not set up or disabled */
+       HV_TSC_PAGE_UNSET = 0,
+       /* TSC page MSR was written by the guest, update pending */
+       HV_TSC_PAGE_GUEST_CHANGED,
+       /* TSC page MSR was written by KVM userspace, update pending */
+       HV_TSC_PAGE_HOST_CHANGED,
+       /* TSC page was properly set up and is currently active  */
+       HV_TSC_PAGE_SET,
+       /* TSC page is currently being updated and therefore is inactive */
+       HV_TSC_PAGE_UPDATING,
+       /* TSC page was set up with an inaccessible GPA */
+       HV_TSC_PAGE_BROKEN,
+};
+
 /* Hyper-V emulation context */
 struct kvm_hv {
        struct mutex hv_lock;
        u64 hv_guest_os_id;
        u64 hv_hypercall;
        u64 hv_tsc_page;
+       enum hv_tsc_page_status hv_tsc_page_status;
 
        /* Hyper-v based guest crash (NT kernel bugcheck) parameters */
        u64 hv_crash_param[HV_X64_MSR_CRASH_PARAMS];
@@ -931,6 +948,12 @@ enum kvm_irqchip_mode {
        KVM_IRQCHIP_SPLIT,        /* created with KVM_CAP_SPLIT_IRQCHIP */
 };
 
+struct kvm_x86_msr_filter {
+       u8 count;
+       bool default_allow:1;
+       struct msr_bitmap_range ranges[16];
+};
+
 #define APICV_INHIBIT_REASON_DISABLE    0
 #define APICV_INHIBIT_REASON_HYPERV     1
 #define APICV_INHIBIT_REASON_NESTED     2
@@ -1025,16 +1048,11 @@ struct kvm_arch {
        bool guest_can_read_msr_platform_info;
        bool exception_payload_enabled;
 
+       bool bus_lock_detection_enabled;
+
        /* Deflect RDMSR and WRMSR to user space when they trigger a #GP */
        u32 user_space_msr_mask;
-
-       struct {
-               u8 count;
-               bool default_allow:1;
-               struct msr_bitmap_range ranges[16];
-       } msr_filter;
-
-       bool bus_lock_detection_enabled;
+       struct kvm_x86_msr_filter __rcu *msr_filter;
 
        struct kvm_pmu_event_filter __rcu *pmu_event_filter;
        struct task_struct *nx_lpage_recovery_thread;
index 5e78e01..78bb0fa 100644 (file)
@@ -836,28 +836,25 @@ static void kvm_kick_cpu(int cpu)
 
 static void kvm_wait(u8 *ptr, u8 val)
 {
-       unsigned long flags;
-
        if (in_nmi())
                return;
 
-       local_irq_save(flags);
-
-       if (READ_ONCE(*ptr) != val)
-               goto out;
-
        /*
         * halt until it's our turn and kicked. Note that we do safe halt
         * for irq enabled case to avoid hang when lock info is overwritten
         * in irq spinlock slowpath and no spurious interrupt occur to save us.
         */
-       if (arch_irqs_disabled_flags(flags))
-               halt();
-       else
-               safe_halt();
+       if (irqs_disabled()) {
+               if (READ_ONCE(*ptr) == val)
+                       halt();
+       } else {
+               local_irq_disable();
 
-out:
-       local_irq_restore(flags);
+               if (READ_ONCE(*ptr) == val)
+                       safe_halt();
+
+               local_irq_enable();
+       }
 }
 
 #ifdef CONFIG_X86_32
index 58fa8c0..f98370a 100644 (file)
@@ -520,10 +520,10 @@ static u64 get_time_ref_counter(struct kvm *kvm)
        u64 tsc;
 
        /*
-        * The guest has not set up the TSC page or the clock isn't
-        * stable, fall back to get_kvmclock_ns.
+        * Fall back to get_kvmclock_ns() when TSC page hasn't been set up,
+        * is broken, disabled or being updated.
         */
-       if (!hv->tsc_ref.tsc_sequence)
+       if (hv->hv_tsc_page_status != HV_TSC_PAGE_SET)
                return div_u64(get_kvmclock_ns(kvm), 100);
 
        vcpu = kvm_get_vcpu(kvm, 0);
@@ -1077,6 +1077,21 @@ static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
        return true;
 }
 
+/*
+ * Don't touch TSC page values if the guest has opted for TSC emulation after
+ * migration. KVM doesn't fully support reenlightenment notifications and TSC
+ * access emulation and Hyper-V is known to expect the values in TSC page to
+ * stay constant before TSC access emulation is disabled from guest side
+ * (HV_X64_MSR_TSC_EMULATION_STATUS). KVM userspace is expected to preserve TSC
+ * frequency and guest visible TSC value across migration (and prevent it when
+ * TSC scaling is unsupported).
+ */
+static inline bool tsc_page_update_unsafe(struct kvm_hv *hv)
+{
+       return (hv->hv_tsc_page_status != HV_TSC_PAGE_GUEST_CHANGED) &&
+               hv->hv_tsc_emulation_control;
+}
+
 void kvm_hv_setup_tsc_page(struct kvm *kvm,
                           struct pvclock_vcpu_time_info *hv_clock)
 {
@@ -1087,7 +1102,8 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
        BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
        BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
 
-       if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
+       if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
+           hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET)
                return;
 
        mutex_lock(&hv->hv_lock);
@@ -1101,7 +1117,15 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
         */
        if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
                                    &tsc_seq, sizeof(tsc_seq))))
+               goto out_err;
+
+       if (tsc_seq && tsc_page_update_unsafe(hv)) {
+               if (kvm_read_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
+                       goto out_err;
+
+               hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
                goto out_unlock;
+       }
 
        /*
         * While we're computing and writing the parameters, force the
@@ -1110,15 +1134,15 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
        hv->tsc_ref.tsc_sequence = 0;
        if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
                            &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
-               goto out_unlock;
+               goto out_err;
 
        if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
-               goto out_unlock;
+               goto out_err;
 
        /* Ensure sequence is zero before writing the rest of the struct.  */
        smp_wmb();
        if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
-               goto out_unlock;
+               goto out_err;
 
        /*
         * Now switch to the TSC page mechanism by writing the sequence.
@@ -1131,8 +1155,45 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
        smp_wmb();
 
        hv->tsc_ref.tsc_sequence = tsc_seq;
-       kvm_write_guest(kvm, gfn_to_gpa(gfn),
-                       &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence));
+       if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
+                           &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
+               goto out_err;
+
+       hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
+       goto out_unlock;
+
+out_err:
+       hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
+out_unlock:
+       mutex_unlock(&hv->hv_lock);
+}
+
+void kvm_hv_invalidate_tsc_page(struct kvm *kvm)
+{
+       struct kvm_hv *hv = to_kvm_hv(kvm);
+       u64 gfn;
+
+       if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
+           hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET ||
+           tsc_page_update_unsafe(hv))
+               return;
+
+       mutex_lock(&hv->hv_lock);
+
+       if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
+               goto out_unlock;
+
+       /* Preserve HV_TSC_PAGE_GUEST_CHANGED/HV_TSC_PAGE_HOST_CHANGED states */
+       if (hv->hv_tsc_page_status == HV_TSC_PAGE_SET)
+               hv->hv_tsc_page_status = HV_TSC_PAGE_UPDATING;
+
+       gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
+
+       hv->tsc_ref.tsc_sequence = 0;
+       if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
+                           &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
+               hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
+
 out_unlock:
        mutex_unlock(&hv->hv_lock);
 }
@@ -1193,8 +1254,15 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
        }
        case HV_X64_MSR_REFERENCE_TSC:
                hv->hv_tsc_page = data;
-               if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)
+               if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) {
+                       if (!host)
+                               hv->hv_tsc_page_status = HV_TSC_PAGE_GUEST_CHANGED;
+                       else
+                               hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
                        kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
+               } else {
+                       hv->hv_tsc_page_status = HV_TSC_PAGE_UNSET;
+               }
                break;
        case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
                return kvm_hv_msr_set_crash_data(kvm,
@@ -1229,6 +1297,9 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
                hv->hv_tsc_emulation_control = data;
                break;
        case HV_X64_MSR_TSC_EMULATION_STATUS:
+               if (data && !host)
+                       return 1;
+
                hv->hv_tsc_emulation_status = data;
                break;
        case HV_X64_MSR_TIME_REF_COUNT:
index e951af1..60547d5 100644 (file)
@@ -133,6 +133,7 @@ void kvm_hv_process_stimers(struct kvm_vcpu *vcpu);
 
 void kvm_hv_setup_tsc_page(struct kvm *kvm,
                           struct pvclock_vcpu_time_info *hv_clock);
+void kvm_hv_invalidate_tsc_page(struct kvm *kvm);
 
 void kvm_hv_init_vm(struct kvm *kvm);
 void kvm_hv_destroy_vm(struct kvm *kvm);
index ec4fc28..1f6f98c 100644 (file)
@@ -78,6 +78,11 @@ static inline struct kvm_mmu_page *sptep_to_sp(u64 *sptep)
        return to_shadow_page(__pa(sptep));
 }
 
+static inline int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)
+{
+       return sp->role.smm ? 1 : 0;
+}
+
 static inline bool kvm_vcpu_ad_need_write_protect(struct kvm_vcpu *vcpu)
 {
        /*
index e5f1481..b3ed302 100644 (file)
@@ -20,6 +20,21 @@ static gfn_t round_gfn_for_level(gfn_t gfn, int level)
        return gfn & -KVM_PAGES_PER_HPAGE(level);
 }
 
+/*
+ * Return the TDP iterator to the root PT and allow it to continue its
+ * traversal over the paging structure from there.
+ */
+void tdp_iter_restart(struct tdp_iter *iter)
+{
+       iter->yielded_gfn = iter->next_last_level_gfn;
+       iter->level = iter->root_level;
+
+       iter->gfn = round_gfn_for_level(iter->next_last_level_gfn, iter->level);
+       tdp_iter_refresh_sptep(iter);
+
+       iter->valid = true;
+}
+
 /*
  * Sets a TDP iterator to walk a pre-order traversal of the paging structure
  * rooted at root_pt, starting with the walk to translate next_last_level_gfn.
@@ -31,16 +46,12 @@ void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level,
        WARN_ON(root_level > PT64_ROOT_MAX_LEVEL);
 
        iter->next_last_level_gfn = next_last_level_gfn;
-       iter->yielded_gfn = iter->next_last_level_gfn;
        iter->root_level = root_level;
        iter->min_level = min_level;
-       iter->level = root_level;
-       iter->pt_path[iter->level - 1] = (tdp_ptep_t)root_pt;
-
-       iter->gfn = round_gfn_for_level(iter->next_last_level_gfn, iter->level);
-       tdp_iter_refresh_sptep(iter);
+       iter->pt_path[iter->root_level - 1] = (tdp_ptep_t)root_pt;
+       iter->as_id = kvm_mmu_page_as_id(sptep_to_sp(root_pt));
 
-       iter->valid = true;
+       tdp_iter_restart(iter);
 }
 
 /*
@@ -159,8 +170,3 @@ void tdp_iter_next(struct tdp_iter *iter)
        iter->valid = false;
 }
 
-tdp_ptep_t tdp_iter_root_pt(struct tdp_iter *iter)
-{
-       return iter->pt_path[iter->root_level - 1];
-}
-
index 4cc177d..b1748b9 100644 (file)
@@ -36,6 +36,8 @@ struct tdp_iter {
        int min_level;
        /* The iterator's current level within the paging structure */
        int level;
+       /* The address space ID, i.e. SMM vs. regular. */
+       int as_id;
        /* A snapshot of the value at sptep */
        u64 old_spte;
        /*
@@ -62,6 +64,6 @@ tdp_ptep_t spte_to_child_pt(u64 pte, int level);
 void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level,
                    int min_level, gfn_t next_last_level_gfn);
 void tdp_iter_next(struct tdp_iter *iter);
-tdp_ptep_t tdp_iter_root_pt(struct tdp_iter *iter);
+void tdp_iter_restart(struct tdp_iter *iter);
 
 #endif /* __KVM_X86_MMU_TDP_ITER_H */
index d789150..462b1f7 100644 (file)
@@ -203,11 +203,6 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
                                u64 old_spte, u64 new_spte, int level,
                                bool shared);
 
-static int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)
-{
-       return sp->role.smm ? 1 : 0;
-}
-
 static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
 {
        bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
@@ -301,11 +296,16 @@ static void tdp_mmu_unlink_page(struct kvm *kvm, struct kvm_mmu_page *sp,
  *
  * Given a page table that has been removed from the TDP paging structure,
  * iterates through the page table to clear SPTEs and free child page tables.
+ *
+ * Note that pt is passed in as a tdp_ptep_t, but it does not need RCU
+ * protection. Since this thread removed it from the paging structure,
+ * this thread will be responsible for ensuring the page is freed. Hence the
+ * early rcu_dereferences in the function.
  */
-static void handle_removed_tdp_mmu_page(struct kvm *kvm, u64 *pt,
+static void handle_removed_tdp_mmu_page(struct kvm *kvm, tdp_ptep_t pt,
                                        bool shared)
 {
-       struct kvm_mmu_page *sp = sptep_to_sp(pt);
+       struct kvm_mmu_page *sp = sptep_to_sp(rcu_dereference(pt));
        int level = sp->role.level;
        gfn_t base_gfn = sp->gfn;
        u64 old_child_spte;
@@ -318,7 +318,7 @@ static void handle_removed_tdp_mmu_page(struct kvm *kvm, u64 *pt,
        tdp_mmu_unlink_page(kvm, sp, shared);
 
        for (i = 0; i < PT64_ENT_PER_PAGE; i++) {
-               sptep = pt + i;
+               sptep = rcu_dereference(pt) + i;
                gfn = base_gfn + (i * KVM_PAGES_PER_HPAGE(level - 1));
 
                if (shared) {
@@ -492,10 +492,6 @@ static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm,
                                           struct tdp_iter *iter,
                                           u64 new_spte)
 {
-       u64 *root_pt = tdp_iter_root_pt(iter);
-       struct kvm_mmu_page *root = sptep_to_sp(root_pt);
-       int as_id = kvm_mmu_page_as_id(root);
-
        lockdep_assert_held_read(&kvm->mmu_lock);
 
        /*
@@ -509,8 +505,8 @@ static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm,
                      new_spte) != iter->old_spte)
                return false;
 
-       handle_changed_spte(kvm, as_id, iter->gfn, iter->old_spte, new_spte,
-                           iter->level, true);
+       handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
+                           new_spte, iter->level, true);
 
        return true;
 }
@@ -538,7 +534,7 @@ static inline bool tdp_mmu_zap_spte_atomic(struct kvm *kvm,
         * here since the SPTE is going from non-present
         * to non-present.
         */
-       WRITE_ONCE(*iter->sptep, 0);
+       WRITE_ONCE(*rcu_dereference(iter->sptep), 0);
 
        return true;
 }
@@ -564,10 +560,6 @@ static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
                                      u64 new_spte, bool record_acc_track,
                                      bool record_dirty_log)
 {
-       tdp_ptep_t root_pt = tdp_iter_root_pt(iter);
-       struct kvm_mmu_page *root = sptep_to_sp(root_pt);
-       int as_id = kvm_mmu_page_as_id(root);
-
        lockdep_assert_held_write(&kvm->mmu_lock);
 
        /*
@@ -581,13 +573,13 @@ static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter,
 
        WRITE_ONCE(*rcu_dereference(iter->sptep), new_spte);
 
-       __handle_changed_spte(kvm, as_id, iter->gfn, iter->old_spte, new_spte,
-                             iter->level, false);
+       __handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
+                             new_spte, iter->level, false);
        if (record_acc_track)
                handle_changed_spte_acc_track(iter->old_spte, new_spte,
                                              iter->level);
        if (record_dirty_log)
-               handle_changed_spte_dirty_log(kvm, as_id, iter->gfn,
+               handle_changed_spte_dirty_log(kvm, iter->as_id, iter->gfn,
                                              iter->old_spte, new_spte,
                                              iter->level);
 }
@@ -659,9 +651,7 @@ static inline bool tdp_mmu_iter_cond_resched(struct kvm *kvm,
 
                WARN_ON(iter->gfn > iter->next_last_level_gfn);
 
-               tdp_iter_start(iter, iter->pt_path[iter->root_level - 1],
-                              iter->root_level, iter->min_level,
-                              iter->next_last_level_gfn);
+               tdp_iter_restart(iter);
 
                return true;
        }
index 47e021b..fe806e8 100644 (file)
@@ -1526,35 +1526,44 @@ EXPORT_SYMBOL_GPL(kvm_enable_efer_bits);
 
 bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type)
 {
+       struct kvm_x86_msr_filter *msr_filter;
+       struct msr_bitmap_range *ranges;
        struct kvm *kvm = vcpu->kvm;
-       struct msr_bitmap_range *ranges = kvm->arch.msr_filter.ranges;
-       u32 count = kvm->arch.msr_filter.count;
-       u32 i;
-       bool r = kvm->arch.msr_filter.default_allow;
+       bool allowed;
        int idx;
+       u32 i;
 
-       /* MSR filtering not set up or x2APIC enabled, allow everything */
-       if (!count || (index >= 0x800 && index <= 0x8ff))
+       /* x2APIC MSRs do not support filtering. */
+       if (index >= 0x800 && index <= 0x8ff)
                return true;
 
-       /* Prevent collision with set_msr_filter */
        idx = srcu_read_lock(&kvm->srcu);
 
-       for (i = 0; i < count; i++) {
+       msr_filter = srcu_dereference(kvm->arch.msr_filter, &kvm->srcu);
+       if (!msr_filter) {
+               allowed = true;
+               goto out;
+       }
+
+       allowed = msr_filter->default_allow;
+       ranges = msr_filter->ranges;
+
+       for (i = 0; i < msr_filter->count; i++) {
                u32 start = ranges[i].base;
                u32 end = start + ranges[i].nmsrs;
                u32 flags = ranges[i].flags;
                unsigned long *bitmap = ranges[i].bitmap;
 
                if ((index >= start) && (index < end) && (flags & type)) {
-                       r = !!test_bit(index - start, bitmap);
+                       allowed = !!test_bit(index - start, bitmap);
                        break;
                }
        }
 
+out:
        srcu_read_unlock(&kvm->srcu, idx);
 
-       return r;
+       return allowed;
 }
 EXPORT_SYMBOL_GPL(kvm_msr_allowed);
 
@@ -2551,6 +2560,8 @@ static void kvm_gen_update_masterclock(struct kvm *kvm)
        struct kvm_vcpu *vcpu;
        struct kvm_arch *ka = &kvm->arch;
 
+       kvm_hv_invalidate_tsc_page(kvm);
+
        spin_lock(&ka->pvclock_gtod_sync_lock);
        kvm_make_mclock_inprogress_request(kvm);
        /* no guest entries from this point */
@@ -5352,25 +5363,34 @@ split_irqchip_unlock:
        return r;
 }
 
-static void kvm_clear_msr_filter(struct kvm *kvm)
+static struct kvm_x86_msr_filter *kvm_alloc_msr_filter(bool default_allow)
+{
+       struct kvm_x86_msr_filter *msr_filter;
+
+       msr_filter = kzalloc(sizeof(*msr_filter), GFP_KERNEL_ACCOUNT);
+       if (!msr_filter)
+               return NULL;
+
+       msr_filter->default_allow = default_allow;
+       return msr_filter;
+}
+
+static void kvm_free_msr_filter(struct kvm_x86_msr_filter *msr_filter)
 {
        u32 i;
-       u32 count = kvm->arch.msr_filter.count;
-       struct msr_bitmap_range ranges[16];
 
-       mutex_lock(&kvm->lock);
-       kvm->arch.msr_filter.count = 0;
-       memcpy(ranges, kvm->arch.msr_filter.ranges, count * sizeof(ranges[0]));
-       mutex_unlock(&kvm->lock);
-       synchronize_srcu(&kvm->srcu);
+       if (!msr_filter)
+               return;
 
-       for (i = 0; i < count; i++)
-               kfree(ranges[i].bitmap);
+       for (i = 0; i < msr_filter->count; i++)
+               kfree(msr_filter->ranges[i].bitmap);
+
+       kfree(msr_filter);
 }
 
-static int kvm_add_msr_filter(struct kvm *kvm, struct kvm_msr_filter_range *user_range)
+static int kvm_add_msr_filter(struct kvm_x86_msr_filter *msr_filter,
+                             struct kvm_msr_filter_range *user_range)
 {
-       struct msr_bitmap_range *ranges = kvm->arch.msr_filter.ranges;
        struct msr_bitmap_range range;
        unsigned long *bitmap = NULL;
        size_t bitmap_size;
@@ -5404,11 +5424,9 @@ static int kvm_add_msr_filter(struct kvm *kvm, struct kvm_msr_filter_range *user
                goto err;
        }
 
-       /* Everything ok, add this range identifier to our global pool */
-       ranges[kvm->arch.msr_filter.count] = range;
-       /* Make sure we filled the array before we tell anyone to walk it */
-       smp_wmb();
-       kvm->arch.msr_filter.count++;
+       /* Everything ok, add this range identifier. */
+       msr_filter->ranges[msr_filter->count] = range;
+       msr_filter->count++;
 
        return 0;
 err:
@@ -5419,10 +5437,11 @@ err:
 static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp)
 {
        struct kvm_msr_filter __user *user_msr_filter = argp;
+       struct kvm_x86_msr_filter *new_filter, *old_filter;
        struct kvm_msr_filter filter;
        bool default_allow;
-       int r = 0;
        bool empty = true;
+       int r = 0;
        u32 i;
 
        if (copy_from_user(&filter, user_msr_filter, sizeof(filter)))
@@ -5435,25 +5454,32 @@ static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp)
        if (empty && !default_allow)
                return -EINVAL;
 
-       kvm_clear_msr_filter(kvm);
-
-       kvm->arch.msr_filter.default_allow = default_allow;
+       new_filter = kvm_alloc_msr_filter(default_allow);
+       if (!new_filter)
+               return -ENOMEM;
 
-       /*
-        * Protect from concurrent calls to this function that could trigger
-        * a TOCTOU violation on kvm->arch.msr_filter.count.
-        */
-       mutex_lock(&kvm->lock);
        for (i = 0; i < ARRAY_SIZE(filter.ranges); i++) {
-               r = kvm_add_msr_filter(kvm, &filter.ranges[i]);
-               if (r)
-                       break;
+               r = kvm_add_msr_filter(new_filter, &filter.ranges[i]);
+               if (r) {
+                       kvm_free_msr_filter(new_filter);
+                       return r;
+               }
        }
 
+       mutex_lock(&kvm->lock);
+
+       /* The per-VM filter is protected by kvm->lock... */
+       old_filter = srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1);
+
+       rcu_assign_pointer(kvm->arch.msr_filter, new_filter);
+       synchronize_srcu(&kvm->srcu);
+
+       kvm_free_msr_filter(old_filter);
+
        kvm_make_all_cpus_request(kvm, KVM_REQ_MSR_FILTER_CHANGED);
        mutex_unlock(&kvm->lock);
 
-       return r;
+       return 0;
 }
 
 long kvm_arch_vm_ioctl(struct file *filp,
@@ -6603,7 +6629,7 @@ static int kvm_emulate_wbinvd_noskip(struct kvm_vcpu *vcpu)
                int cpu = get_cpu();
 
                cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
-               smp_call_function_many(vcpu->arch.wbinvd_dirty_mask,
+               on_each_cpu_mask(vcpu->arch.wbinvd_dirty_mask,
                                wbinvd_ipi, NULL, 1);
                put_cpu();
                cpumask_clear(vcpu->arch.wbinvd_dirty_mask);
@@ -10634,8 +10660,6 @@ void kvm_arch_pre_destroy_vm(struct kvm *kvm)
 
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
-       u32 i;
-
        if (current->mm == kvm->mm) {
                /*
                 * Free memory regions allocated on behalf of userspace,
@@ -10651,8 +10675,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
                mutex_unlock(&kvm->slots_lock);
        }
        static_call_cond(kvm_x86_vm_destroy)(kvm);
-       for (i = 0; i < kvm->arch.msr_filter.count; i++)
-               kfree(kvm->arch.msr_filter.ranges[i].bitmap);
+       kvm_free_msr_filter(srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1));
        kvm_pic_destroy(kvm);
        kvm_ioapic_destroy(kvm);
        kvm_free_vcpus(kvm);
index 32b87cc..7bd7e77 100644 (file)
@@ -8,10 +8,13 @@
 /x86_64/debug_regs
 /x86_64/evmcs_test
 /x86_64/get_cpuid_test
+/x86_64/get_msr_index_features
 /x86_64/kvm_pv_test
+/x86_64/hyperv_clock
 /x86_64/hyperv_cpuid
 /x86_64/mmio_warning_test
 /x86_64/platform_info_test
+/x86_64/set_boot_cpu_id
 /x86_64/set_sregs_test
 /x86_64/smm_test
 /x86_64/state_test
index a6d61f4..67eebb5 100644 (file)
@@ -39,12 +39,15 @@ LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c
 LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c
 
 TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test
+TEST_GEN_PROGS_x86_64 += x86_64/get_msr_index_features
 TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
 TEST_GEN_PROGS_x86_64 += x86_64/get_cpuid_test
+TEST_GEN_PROGS_x86_64 += x86_64/hyperv_clock
 TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
 TEST_GEN_PROGS_x86_64 += x86_64/kvm_pv_test
 TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test
 TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test
+TEST_GEN_PROGS_x86_64 += x86_64/set_boot_cpu_id
 TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
 TEST_GEN_PROGS_x86_64 += x86_64/smm_test
 TEST_GEN_PROGS_x86_64 += x86_64/state_test
index 2d7eb69..0f4258e 100644 (file)
@@ -16,6 +16,7 @@
 
 #include "sparsebit.h"
 
+#define KVM_DEV_PATH "/dev/kvm"
 #define KVM_MAX_VCPUS 512
 
 /*
@@ -133,6 +134,7 @@ void vcpu_ioctl(struct kvm_vm *vm, uint32_t vcpuid, unsigned long ioctl,
 int _vcpu_ioctl(struct kvm_vm *vm, uint32_t vcpuid, unsigned long ioctl,
                void *arg);
 void vm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg);
+int _vm_ioctl(struct kvm_vm *vm, unsigned long cmd, void *arg);
 void kvm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg);
 int _kvm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg);
 void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
index e5fbf16..b8849a1 100644 (file)
@@ -1697,11 +1697,16 @@ void vm_ioctl(struct kvm_vm *vm, unsigned long cmd, void *arg)
 {
        int ret;
 
-       ret = ioctl(vm->fd, cmd, arg);
+       ret = _vm_ioctl(vm, cmd, arg);
        TEST_ASSERT(ret == 0, "vm ioctl %lu failed, rc: %i errno: %i (%s)",
                cmd, ret, errno, strerror(errno));
 }
 
+int _vm_ioctl(struct kvm_vm *vm, unsigned long cmd, void *arg)
+{
+       return ioctl(vm->fd, cmd, arg);
+}
+
 /*
  * KVM system ioctl
  *
index 34465dc..91ce1b5 100644 (file)
@@ -10,8 +10,6 @@
 
 #include "sparsebit.h"
 
-#define KVM_DEV_PATH           "/dev/kvm"
-
 struct userspace_mem_region {
        struct kvm_userspace_memory_region region;
        struct sparsebit *unused_phy_pages;
diff --git a/tools/testing/selftests/kvm/x86_64/get_msr_index_features.c b/tools/testing/selftests/kvm/x86_64/get_msr_index_features.c
new file mode 100644 (file)
index 0000000..cb953df
--- /dev/null
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test that KVM_GET_MSR_INDEX_LIST and
+ * KVM_GET_MSR_FEATURE_INDEX_LIST work as intended
+ *
+ * Copyright (C) 2020, Red Hat, Inc.
+ */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+static int kvm_num_index_msrs(int kvm_fd, int nmsrs)
+{
+       struct kvm_msr_list *list;
+       int r;
+
+       list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
+       list->nmsrs = nmsrs;
+       r = ioctl(kvm_fd, KVM_GET_MSR_INDEX_LIST, list);
+       TEST_ASSERT(r == -1 && errno == E2BIG,
+                               "Unexpected result from KVM_GET_MSR_INDEX_LIST probe, r: %i",
+                               r);
+
+       r = list->nmsrs;
+       free(list);
+       return r;
+}
+
+static void test_get_msr_index(void)
+{
+       int old_res, res, kvm_fd, r;
+       struct kvm_msr_list *list;
+
+       kvm_fd = open(KVM_DEV_PATH, O_RDONLY);
+       if (kvm_fd < 0)
+               exit(KSFT_SKIP);
+
+       old_res = kvm_num_index_msrs(kvm_fd, 0);
+       TEST_ASSERT(old_res != 0, "Expecting nmsrs to be > 0");
+
+       if (old_res != 1) {
+               res = kvm_num_index_msrs(kvm_fd, 1);
+               TEST_ASSERT(res > 1, "Expecting nmsrs to be > 1");
+               TEST_ASSERT(res == old_res, "Expecting nmsrs to be identical");
+       }
+
+       list = malloc(sizeof(*list) + old_res * sizeof(list->indices[0]));
+       list->nmsrs = old_res;
+       r = ioctl(kvm_fd, KVM_GET_MSR_INDEX_LIST, list);
+
+       TEST_ASSERT(r == 0,
+                   "Unexpected result from KVM_GET_MSR_FEATURE_INDEX_LIST, r: %i",
+                   r);
+       TEST_ASSERT(list->nmsrs == old_res, "Expecting nmsrs to be identical");
+       free(list);
+
+       close(kvm_fd);
+}
+
+static int kvm_num_feature_msrs(int kvm_fd, int nmsrs)
+{
+       struct kvm_msr_list *list;
+       int r;
+
+       list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
+       list->nmsrs = nmsrs;
+       r = ioctl(kvm_fd, KVM_GET_MSR_FEATURE_INDEX_LIST, list);
+       TEST_ASSERT(r == -1 && errno == E2BIG,
+               "Unexpected result from KVM_GET_MSR_FEATURE_INDEX_LIST probe, r: %i",
+                               r);
+
+       r = list->nmsrs;
+       free(list);
+       return r;
+}
+
+struct kvm_msr_list *kvm_get_msr_feature_list(int kvm_fd, int nmsrs)
+{
+       struct kvm_msr_list *list;
+       int r;
+
+       list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
+       list->nmsrs = nmsrs;
+       r = ioctl(kvm_fd, KVM_GET_MSR_FEATURE_INDEX_LIST, list);
+
+       TEST_ASSERT(r == 0,
+               "Unexpected result from KVM_GET_MSR_FEATURE_INDEX_LIST, r: %i",
+               r);
+
+       return list;
+}
+
+static void test_get_msr_feature(void)
+{
+       int res, old_res, i, kvm_fd;
+       struct kvm_msr_list *feature_list;
+
+       kvm_fd = open(KVM_DEV_PATH, O_RDONLY);
+       if (kvm_fd < 0)
+               exit(KSFT_SKIP);
+
+       old_res = kvm_num_feature_msrs(kvm_fd, 0);
+       TEST_ASSERT(old_res != 0, "Expecting nmsrs to be > 0");
+
+       if (old_res != 1) {
+               res = kvm_num_feature_msrs(kvm_fd, 1);
+               TEST_ASSERT(res > 1, "Expecting nmsrs to be > 1");
+               TEST_ASSERT(res == old_res, "Expecting nmsrs to be identical");
+       }
+
+       feature_list = kvm_get_msr_feature_list(kvm_fd, old_res);
+       TEST_ASSERT(old_res == feature_list->nmsrs,
+                               "Unmatching number of msr indexes");
+
+       for (i = 0; i < feature_list->nmsrs; i++)
+               kvm_get_feature_msr(feature_list->indices[i]);
+
+       free(feature_list);
+       close(kvm_fd);
+}
+
+int main(int argc, char *argv[])
+{
+       if (kvm_check_cap(KVM_CAP_GET_MSR_FEATURES))
+               test_get_msr_feature();
+
+       test_get_msr_index();
+}
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_clock.c b/tools/testing/selftests/kvm/x86_64/hyperv_clock.c
new file mode 100644 (file)
index 0000000..ffbc455
--- /dev/null
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021, Red Hat, Inc.
+ *
+ * Tests for Hyper-V clocksources
+ */
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+struct ms_hyperv_tsc_page {
+       volatile u32 tsc_sequence;
+       u32 reserved1;
+       volatile u64 tsc_scale;
+       volatile s64 tsc_offset;
+} __packed;
+
+#define HV_X64_MSR_GUEST_OS_ID                 0x40000000
+#define HV_X64_MSR_TIME_REF_COUNT              0x40000020
+#define HV_X64_MSR_REFERENCE_TSC               0x40000021
+#define HV_X64_MSR_TSC_FREQUENCY               0x40000022
+#define HV_X64_MSR_REENLIGHTENMENT_CONTROL     0x40000106
+#define HV_X64_MSR_TSC_EMULATION_CONTROL       0x40000107
+
+/* Simplified mul_u64_u64_shr() */
+static inline u64 mul_u64_u64_shr64(u64 a, u64 b)
+{
+       union {
+               u64 ll;
+               struct {
+                       u32 low, high;
+               } l;
+       } rm, rn, rh, a0, b0;
+       u64 c;
+
+       a0.ll = a;
+       b0.ll = b;
+
+       rm.ll = (u64)a0.l.low * b0.l.high;
+       rn.ll = (u64)a0.l.high * b0.l.low;
+       rh.ll = (u64)a0.l.high * b0.l.high;
+
+       rh.l.low = c = rm.l.high + rn.l.high + rh.l.low;
+       rh.l.high = (c >> 32) + rh.l.high;
+
+       return rh.ll;
+}
+
+static inline void nop_loop(void)
+{
+       int i;
+
+       for (i = 0; i < 1000000; i++)
+               asm volatile("nop");
+}
+
+static inline void check_tsc_msr_rdtsc(void)
+{
+       u64 tsc_freq, r1, r2, t1, t2;
+       s64 delta_ns;
+
+       tsc_freq = rdmsr(HV_X64_MSR_TSC_FREQUENCY);
+       GUEST_ASSERT(tsc_freq > 0);
+
+       /* First, check MSR-based clocksource */
+       r1 = rdtsc();
+       t1 = rdmsr(HV_X64_MSR_TIME_REF_COUNT);
+       nop_loop();
+       r2 = rdtsc();
+       t2 = rdmsr(HV_X64_MSR_TIME_REF_COUNT);
+
+       GUEST_ASSERT(r2 > r1 && t2 > t1);
+
+       /* HV_X64_MSR_TIME_REF_COUNT is in 100ns */
+       delta_ns = ((t2 - t1) * 100) - ((r2 - r1) * 1000000000 / tsc_freq);
+       if (delta_ns < 0)
+               delta_ns = -delta_ns;
+
+       /* 1% tolerance */
+       GUEST_ASSERT(delta_ns * 100 < (t2 - t1) * 100);
+}
+
+static inline void check_tsc_msr_tsc_page(struct ms_hyperv_tsc_page *tsc_page)
+{
+       u64 r1, r2, t1, t2;
+
+       /* Compare TSC page clocksource with HV_X64_MSR_TIME_REF_COUNT */
+       t1 = mul_u64_u64_shr64(rdtsc(), tsc_page->tsc_scale) + tsc_page->tsc_offset;
+       r1 = rdmsr(HV_X64_MSR_TIME_REF_COUNT);
+
+       /* 10 ms tolerance */
+       GUEST_ASSERT(r1 >= t1 && r1 - t1 < 100000);
+       nop_loop();
+
+       t2 = mul_u64_u64_shr64(rdtsc(), tsc_page->tsc_scale) + tsc_page->tsc_offset;
+       r2 = rdmsr(HV_X64_MSR_TIME_REF_COUNT);
+       GUEST_ASSERT(r2 >= t1 && r2 - t2 < 100000);
+}
+
+static void guest_main(struct ms_hyperv_tsc_page *tsc_page, vm_paddr_t tsc_page_gpa)
+{
+       u64 tsc_scale, tsc_offset;
+
+       /* Set Guest OS id to enable Hyper-V emulation */
+       GUEST_SYNC(1);
+       wrmsr(HV_X64_MSR_GUEST_OS_ID, (u64)0x8100 << 48);
+       GUEST_SYNC(2);
+
+       check_tsc_msr_rdtsc();
+
+       GUEST_SYNC(3);
+
+       /* Set up TSC page is disabled state, check that it's clean */
+       wrmsr(HV_X64_MSR_REFERENCE_TSC, tsc_page_gpa);
+       GUEST_ASSERT(tsc_page->tsc_sequence == 0);
+       GUEST_ASSERT(tsc_page->tsc_scale == 0);
+       GUEST_ASSERT(tsc_page->tsc_offset == 0);
+
+       GUEST_SYNC(4);
+
+       /* Set up TSC page is enabled state */
+       wrmsr(HV_X64_MSR_REFERENCE_TSC, tsc_page_gpa | 0x1);
+       GUEST_ASSERT(tsc_page->tsc_sequence != 0);
+
+       GUEST_SYNC(5);
+
+       check_tsc_msr_tsc_page(tsc_page);
+
+       GUEST_SYNC(6);
+
+       tsc_offset = tsc_page->tsc_offset;
+       /* Call KVM_SET_CLOCK from userspace, check that TSC page was updated */
+       GUEST_SYNC(7);
+       GUEST_ASSERT(tsc_page->tsc_offset != tsc_offset);
+
+       nop_loop();
+
+       /*
+        * Enable Re-enlightenment and check that TSC page stays constant across
+        * KVM_SET_CLOCK.
+        */
+       wrmsr(HV_X64_MSR_REENLIGHTENMENT_CONTROL, 0x1 << 16 | 0xff);
+       wrmsr(HV_X64_MSR_TSC_EMULATION_CONTROL, 0x1);
+       tsc_offset = tsc_page->tsc_offset;
+       tsc_scale = tsc_page->tsc_scale;
+       GUEST_SYNC(8);
+       GUEST_ASSERT(tsc_page->tsc_offset == tsc_offset);
+       GUEST_ASSERT(tsc_page->tsc_scale == tsc_scale);
+
+       GUEST_SYNC(9);
+
+       check_tsc_msr_tsc_page(tsc_page);
+
+       /*
+        * Disable re-enlightenment and TSC page, check that KVM doesn't update
+        * it anymore.
+        */
+       wrmsr(HV_X64_MSR_REENLIGHTENMENT_CONTROL, 0);
+       wrmsr(HV_X64_MSR_TSC_EMULATION_CONTROL, 0);
+       wrmsr(HV_X64_MSR_REFERENCE_TSC, 0);
+       memset(tsc_page, 0, sizeof(*tsc_page));
+
+       GUEST_SYNC(10);
+       GUEST_ASSERT(tsc_page->tsc_sequence == 0);
+       GUEST_ASSERT(tsc_page->tsc_offset == 0);
+       GUEST_ASSERT(tsc_page->tsc_scale == 0);
+
+       GUEST_DONE();
+}
+
+#define VCPU_ID 0
+
+static void host_check_tsc_msr_rdtsc(struct kvm_vm *vm)
+{
+       u64 tsc_freq, r1, r2, t1, t2;
+       s64 delta_ns;
+
+       tsc_freq = vcpu_get_msr(vm, VCPU_ID, HV_X64_MSR_TSC_FREQUENCY);
+       TEST_ASSERT(tsc_freq > 0, "TSC frequency must be nonzero");
+
+       /* First, check MSR-based clocksource */
+       r1 = rdtsc();
+       t1 = vcpu_get_msr(vm, VCPU_ID, HV_X64_MSR_TIME_REF_COUNT);
+       nop_loop();
+       r2 = rdtsc();
+       t2 = vcpu_get_msr(vm, VCPU_ID, HV_X64_MSR_TIME_REF_COUNT);
+
+       TEST_ASSERT(t2 > t1, "Time reference MSR is not monotonic (%ld <= %ld)", t1, t2);
+
+       /* HV_X64_MSR_TIME_REF_COUNT is in 100ns */
+       delta_ns = ((t2 - t1) * 100) - ((r2 - r1) * 1000000000 / tsc_freq);
+       if (delta_ns < 0)
+               delta_ns = -delta_ns;
+
+       /* 1% tolerance */
+       TEST_ASSERT(delta_ns * 100 < (t2 - t1) * 100,
+                   "Elapsed time does not match (MSR=%ld, TSC=%ld)",
+                   (t2 - t1) * 100, (r2 - r1) * 1000000000 / tsc_freq);
+}
+
+int main(void)
+{
+       struct kvm_vm *vm;
+       struct kvm_run *run;
+       struct ucall uc;
+       vm_vaddr_t tsc_page_gva;
+       int stage;
+
+       vm = vm_create_default(VCPU_ID, 0, guest_main);
+       run = vcpu_state(vm, VCPU_ID);
+
+       vcpu_set_hv_cpuid(vm, VCPU_ID);
+
+       tsc_page_gva = vm_vaddr_alloc(vm, getpagesize(), 0x10000, 0, 0);
+       memset(addr_gpa2hva(vm, tsc_page_gva), 0x0, getpagesize());
+       TEST_ASSERT((addr_gva2gpa(vm, tsc_page_gva) & (getpagesize() - 1)) == 0,
+               "TSC page has to be page aligned\n");
+       vcpu_args_set(vm, VCPU_ID, 2, tsc_page_gva, addr_gva2gpa(vm, tsc_page_gva));
+
+       host_check_tsc_msr_rdtsc(vm);
+
+       for (stage = 1;; stage++) {
+               _vcpu_run(vm, VCPU_ID);
+               TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+                           "Stage %d: unexpected exit reason: %u (%s),\n",
+                           stage, run->exit_reason,
+                           exit_reason_str(run->exit_reason));
+
+               switch (get_ucall(vm, VCPU_ID, &uc)) {
+               case UCALL_ABORT:
+                       TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
+                                 __FILE__, uc.args[1]);
+                       /* NOT REACHED */
+               case UCALL_SYNC:
+                       break;
+               case UCALL_DONE:
+                       /* Keep in sync with guest_main() */
+                       TEST_ASSERT(stage == 11, "Testing ended prematurely, stage %d\n",
+                                   stage);
+                       goto out;
+               default:
+                       TEST_FAIL("Unknown ucall %lu", uc.cmd);
+               }
+
+               TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
+                           uc.args[1] == stage,
+                           "Stage %d: Unexpected register values vmexit, got %lx",
+                           stage, (ulong)uc.args[1]);
+
+               /* Reset kvmclock triggering TSC page update */
+               if (stage == 7 || stage == 8 || stage == 10) {
+                       struct kvm_clock_data clock = {0};
+
+                       vm_ioctl(vm, KVM_SET_CLOCK, &clock);
+               }
+       }
+
+out:
+       kvm_vm_free(vm);
+}
diff --git a/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c b/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c
new file mode 100644 (file)
index 0000000..12c558f
--- /dev/null
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test that KVM_SET_BOOT_CPU_ID works as intended
+ *
+ * Copyright (C) 2020, Red Hat, Inc.
+ */
+#define _GNU_SOURCE /* for program_invocation_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+
+#define N_VCPU 2
+#define VCPU_ID0 0
+#define VCPU_ID1 1
+
+static uint32_t get_bsp_flag(void)
+{
+       return rdmsr(MSR_IA32_APICBASE) & MSR_IA32_APICBASE_BSP;
+}
+
+static void guest_bsp_vcpu(void *arg)
+{
+       GUEST_SYNC(1);
+
+       GUEST_ASSERT(get_bsp_flag() != 0);
+
+       GUEST_DONE();
+}
+
+static void guest_not_bsp_vcpu(void *arg)
+{
+       GUEST_SYNC(1);
+
+       GUEST_ASSERT(get_bsp_flag() == 0);
+
+       GUEST_DONE();
+}
+
+static void test_set_boot_busy(struct kvm_vm *vm)
+{
+       int res;
+
+       res = _vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *) VCPU_ID0);
+       TEST_ASSERT(res == -1 && errno == EBUSY,
+                       "KVM_SET_BOOT_CPU_ID set while running vm");
+}
+
+static void run_vcpu(struct kvm_vm *vm, uint32_t vcpuid)
+{
+       struct ucall uc;
+       int stage;
+
+       for (stage = 0; stage < 2; stage++) {
+
+               vcpu_run(vm, vcpuid);
+
+               switch (get_ucall(vm, vcpuid, &uc)) {
+               case UCALL_SYNC:
+                       TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
+                                       uc.args[1] == stage + 1,
+                                       "Stage %d: Unexpected register values vmexit, got %lx",
+                                       stage + 1, (ulong)uc.args[1]);
+                       test_set_boot_busy(vm);
+                       break;
+               case UCALL_DONE:
+                       TEST_ASSERT(stage == 1,
+                                       "Expected GUEST_DONE in stage 2, got stage %d",
+                                       stage);
+                       break;
+               case UCALL_ABORT:
+                       TEST_ASSERT(false, "%s at %s:%ld\n\tvalues: %#lx, %#lx",
+                                               (const char *)uc.args[0], __FILE__,
+                                               uc.args[1], uc.args[2], uc.args[3]);
+               default:
+                       TEST_ASSERT(false, "Unexpected exit: %s",
+                                       exit_reason_str(vcpu_state(vm, vcpuid)->exit_reason));
+               }
+       }
+}
+
+static struct kvm_vm *create_vm(void)
+{
+       struct kvm_vm *vm;
+       uint64_t vcpu_pages = (DEFAULT_STACK_PGS) * 2;
+       uint64_t extra_pg_pages = vcpu_pages / PTES_PER_MIN_PAGE * N_VCPU;
+       uint64_t pages = DEFAULT_GUEST_PHY_PAGES + vcpu_pages + extra_pg_pages;
+
+       pages = vm_adjust_num_guest_pages(VM_MODE_DEFAULT, pages);
+       vm = vm_create(VM_MODE_DEFAULT, pages, O_RDWR);
+
+       kvm_vm_elf_load(vm, program_invocation_name, 0, 0);
+       vm_create_irqchip(vm);
+
+       return vm;
+}
+
+static void add_x86_vcpu(struct kvm_vm *vm, uint32_t vcpuid, bool bsp_code)
+{
+       if (bsp_code)
+               vm_vcpu_add_default(vm, vcpuid, guest_bsp_vcpu);
+       else
+               vm_vcpu_add_default(vm, vcpuid, guest_not_bsp_vcpu);
+
+       vcpu_set_cpuid(vm, vcpuid, kvm_get_supported_cpuid());
+}
+
+static void run_vm_bsp(uint32_t bsp_vcpu)
+{
+       struct kvm_vm *vm;
+       bool is_bsp_vcpu1 = bsp_vcpu == VCPU_ID1;
+
+       vm = create_vm();
+
+       if (is_bsp_vcpu1)
+               vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *) VCPU_ID1);
+
+       add_x86_vcpu(vm, VCPU_ID0, !is_bsp_vcpu1);
+       add_x86_vcpu(vm, VCPU_ID1, is_bsp_vcpu1);
+
+       run_vcpu(vm, VCPU_ID0);
+       run_vcpu(vm, VCPU_ID1);
+
+       kvm_vm_free(vm);
+}
+
+static void check_set_bsp_busy(void)
+{
+       struct kvm_vm *vm;
+       int res;
+
+       vm = create_vm();
+
+       add_x86_vcpu(vm, VCPU_ID0, true);
+       add_x86_vcpu(vm, VCPU_ID1, false);
+
+       res = _vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *) VCPU_ID1);
+       TEST_ASSERT(res == -1 && errno == EBUSY, "KVM_SET_BOOT_CPU_ID set after adding vcpu");
+
+       run_vcpu(vm, VCPU_ID0);
+       run_vcpu(vm, VCPU_ID1);
+
+       res = _vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *) VCPU_ID1);
+       TEST_ASSERT(res == -1 && errno == EBUSY, "KVM_SET_BOOT_CPU_ID set to a terminated vcpu");
+
+       kvm_vm_free(vm);
+}
+
+int main(int argc, char *argv[])
+{
+       if (!kvm_check_cap(KVM_CAP_SET_BOOT_CPU_ID)) {
+               print_skip("set_boot_cpu_id not available");
+               return 0;
+       }
+
+       run_vm_bsp(VCPU_ID0);
+       run_vm_bsp(VCPU_ID1);
+       run_vm_bsp(VCPU_ID0);
+
+       check_set_bsp_busy();
+}