KVM: x86/mmu: split cpu_role from mmu_role

Snapshot the state of the processor registers that govern page walk into
a new field of struct kvm_mmu.  This is a more natural representation
than having it *mostly* in mmu_role but not exclusively; the delta
right now is represented in other fields, such as root_level.

The nested MMU now has only the CPU role; and in fact the new function
kvm_calc_cpu_role is analogous to the previous kvm_calc_nested_mmu_role,
except that it has role.base.direct equal to !CR0.PG.  For a walk-only
MMU, "direct" has no meaning, but we set it to !CR0.PG so that
role.ext.cr0_pg can go away in a future patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e46bd28..50edf52 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -438,6 +438,7 @@ struct kvm_mmu {
                         struct kvm_mmu_page *sp);
        void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa);
        struct kvm_mmu_root_info root;
+       union kvm_mmu_role cpu_role;
        union kvm_mmu_role mmu_role;
        u8 root_level;
        u8 shadow_root_level;

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 8b49b1e..81c9e5e 100644 (file)
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -222,7 +222,7 @@ BUILD_MMU_ROLE_REGS_ACCESSOR(efer, lma, EFER_LMA);
 #define BUILD_MMU_ROLE_ACCESSOR(base_or_ext, reg, name)                \
 static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu)       \
 {                                                              \
-       return !!(mmu->mmu_role. base_or_ext . reg##_##name);   \
+       return !!(mmu->cpu_role. base_or_ext . reg##_##name);   \
 }
 BUILD_MMU_ROLE_ACCESSOR(ext,  cr0, pg);
 BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp);
@@ -4748,6 +4748,41 @@ static void paging32_init_context(struct kvm_mmu *context)
        context->direct_map = false;
 }
 
+static union kvm_mmu_role
+kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs)
+{
+       union kvm_mmu_role role = {0};
+
+       role.base.access = ACC_ALL;
+       role.base.smm = is_smm(vcpu);
+       role.base.guest_mode = is_guest_mode(vcpu);
+       role.ext.valid = 1;
+
+       if (!____is_cr0_pg(regs)) {
+               role.base.direct = 1;
+               return role;
+       }
+
+       role.base.efer_nx = ____is_efer_nx(regs);
+       role.base.cr0_wp = ____is_cr0_wp(regs);
+       role.base.smep_andnot_wp = ____is_cr4_smep(regs) && !____is_cr0_wp(regs);
+       role.base.smap_andnot_wp = ____is_cr4_smap(regs) && !____is_cr0_wp(regs);
+       role.base.has_4_byte_gpte = !____is_cr4_pae(regs);
+       role.base.level = role_regs_to_root_level(regs);
+
+       role.ext.cr0_pg = 1;
+       role.ext.cr4_pae = ____is_cr4_pae(regs);
+       role.ext.cr4_smep = ____is_cr4_smep(regs);
+       role.ext.cr4_smap = ____is_cr4_smap(regs);
+       role.ext.cr4_pse = ____is_cr4_pse(regs);
+
+       /* PKEY and LA57 are active iff long mode is active. */
+       role.ext.cr4_pke = ____is_efer_lma(regs) && ____is_cr4_pke(regs);
+       role.ext.cr4_la57 = ____is_efer_lma(regs) && ____is_cr4_la57(regs);
+       role.ext.efer_lma = ____is_efer_lma(regs);
+       return role;
+}
+
 static union kvm_mmu_role kvm_calc_mmu_role_common(struct kvm_vcpu *vcpu,
                                                   const struct kvm_mmu_role_regs *regs)
 {
@@ -4807,13 +4842,16 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
                             const struct kvm_mmu_role_regs *regs)
 {
        struct kvm_mmu *context = &vcpu->arch.root_mmu;
-       union kvm_mmu_role new_role =
+       union kvm_mmu_role cpu_role = kvm_calc_cpu_role(vcpu, regs);
+       union kvm_mmu_role mmu_role =
                kvm_calc_tdp_mmu_root_page_role(vcpu, regs);
 
-       if (new_role.as_u64 == context->mmu_role.as_u64)
+       if (cpu_role.as_u64 == context->cpu_role.as_u64 &&
+           mmu_role.as_u64 == context->mmu_role.as_u64)
                return;
 
-       context->mmu_role.as_u64 = new_role.as_u64;
+       context->cpu_role.as_u64 = cpu_role.as_u64;
+       context->mmu_role.as_u64 = mmu_role.as_u64;
        context->page_fault = kvm_tdp_page_fault;
        context->sync_page = nonpaging_sync_page;
        context->invlpg = NULL;
@@ -4868,13 +4906,15 @@ kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu,
 }
 
 static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context,
-                                   const struct kvm_mmu_role_regs *regs,
-                                   union kvm_mmu_role new_role)
+                                   union kvm_mmu_role cpu_role,
+                                   union kvm_mmu_role mmu_role)
 {
-       if (new_role.as_u64 == context->mmu_role.as_u64)
+       if (cpu_role.as_u64 == context->cpu_role.as_u64 &&
+           mmu_role.as_u64 == context->mmu_role.as_u64)
                return;
 
-       context->mmu_role.as_u64 = new_role.as_u64;
+       context->cpu_role.as_u64 = cpu_role.as_u64;
+       context->mmu_role.as_u64 = mmu_role.as_u64;
 
        if (!is_cr0_pg(context))
                nonpaging_init_context(context);
@@ -4882,10 +4922,10 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *conte
                paging64_init_context(context);
        else
                paging32_init_context(context);
-       context->root_level = role_regs_to_root_level(regs);
+       context->root_level = cpu_role.base.level;
 
        reset_guest_paging_metadata(vcpu, context);
-       context->shadow_root_level = new_role.base.level;
+       context->shadow_root_level = mmu_role.base.level;
 
        reset_shadow_zero_bits_mask(vcpu, context);
 }
@@ -4894,10 +4934,11 @@ static void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu,
                                const struct kvm_mmu_role_regs *regs)
 {
        struct kvm_mmu *context = &vcpu->arch.root_mmu;
-       union kvm_mmu_role new_role =
+       union kvm_mmu_role cpu_role = kvm_calc_cpu_role(vcpu, regs);
+       union kvm_mmu_role mmu_role =
                kvm_calc_shadow_mmu_root_page_role(vcpu, regs);
 
-       shadow_mmu_init_context(vcpu, context, regs, new_role);
+       shadow_mmu_init_context(vcpu, context, cpu_role, mmu_role);
 }
 
 static union kvm_mmu_role
@@ -4922,11 +4963,10 @@ void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
                .cr4 = cr4 & ~X86_CR4_PKE,
                .efer = efer,
        };
-       union kvm_mmu_role new_role;
-
-       new_role = kvm_calc_shadow_npt_root_page_role(vcpu, &regs);
+       union kvm_mmu_role cpu_role = kvm_calc_cpu_role(vcpu, &regs);
+       union kvm_mmu_role mmu_role = kvm_calc_shadow_npt_root_page_role(vcpu, &regs);
 
-       shadow_mmu_init_context(vcpu, context, &regs, new_role);
+       shadow_mmu_init_context(vcpu, context, cpu_role, mmu_role);
        kvm_mmu_new_pgd(vcpu, nested_cr3);
 }
 EXPORT_SYMBOL_GPL(kvm_init_shadow_npt_mmu);
@@ -4949,7 +4989,6 @@ kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty,
        role.base.guest_mode = true;
        role.base.access = ACC_ALL;
 
-       /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */
        role.ext.word = 0;
        role.ext.execonly = execonly;
        role.ext.valid = 1;
@@ -4963,12 +5002,14 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
 {
        struct kvm_mmu *context = &vcpu->arch.guest_mmu;
        u8 level = vmx_eptp_page_walk_level(new_eptp);
-       union kvm_mmu_role new_role =
+       union kvm_mmu_role new_mode =
                kvm_calc_shadow_ept_root_page_role(vcpu, accessed_dirty,
                                                   execonly, level);
 
-       if (new_role.as_u64 != context->mmu_role.as_u64) {
-               context->mmu_role.as_u64 = new_role.as_u64;
+       if (new_mode.as_u64 != context->cpu_role.as_u64) {
+               /* EPT, and thus nested EPT, does not consume CR0, CR4, nor EFER. */
+               context->cpu_role.as_u64 = new_mode.as_u64;
+               context->mmu_role.as_u64 = new_mode.as_u64;
 
                context->shadow_root_level = level;
 
@@ -5001,37 +5042,20 @@ static void init_kvm_softmmu(struct kvm_vcpu *vcpu,
        context->inject_page_fault = kvm_inject_page_fault;
 }
 
-static union kvm_mmu_role
-kvm_calc_nested_mmu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs)
-{
-       union kvm_mmu_role role;
-
-       role = kvm_calc_shadow_root_page_role_common(vcpu, regs);
-
-       /*
-        * Nested MMUs are used only for walking L2's gva->gpa, they never have
-        * shadow pages of their own and so "direct" has no meaning.   Set it
-        * to "true" to try to detect bogus usage of the nested MMU.
-        */
-       role.base.direct = true;
-       role.base.level = role_regs_to_root_level(regs);
-       return role;
-}
-
 static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu,
                                const struct kvm_mmu_role_regs *regs)
 {
-       union kvm_mmu_role new_role = kvm_calc_nested_mmu_role(vcpu, regs);
+       union kvm_mmu_role new_mode = kvm_calc_cpu_role(vcpu, regs);
        struct kvm_mmu *g_context = &vcpu->arch.nested_mmu;
 
-       if (new_role.as_u64 == g_context->mmu_role.as_u64)
+       if (new_mode.as_u64 == g_context->cpu_role.as_u64)
                return;
 
-       g_context->mmu_role.as_u64 = new_role.as_u64;
+       g_context->cpu_role.as_u64   = new_mode.as_u64;
        g_context->get_guest_pgd     = get_cr3;
        g_context->get_pdptr         = kvm_pdptr_read;
        g_context->inject_page_fault = kvm_inject_page_fault;
-       g_context->root_level        = new_role.base.level;
+       g_context->root_level        = new_mode.base.level;
 
        /*
         * L2 page tables are never shadowed, so there is no need to sync
@@ -5089,6 +5113,9 @@ void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu)
        vcpu->arch.root_mmu.mmu_role.ext.valid = 0;
        vcpu->arch.guest_mmu.mmu_role.ext.valid = 0;
        vcpu->arch.nested_mmu.mmu_role.ext.valid = 0;
+       vcpu->arch.root_mmu.cpu_role.ext.valid = 0;
+       vcpu->arch.guest_mmu.cpu_role.ext.valid = 0;
+       vcpu->arch.nested_mmu.cpu_role.ext.valid = 0;
        kvm_mmu_reset_context(vcpu);
 
        /*

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 07a7832..56544c5 100644 (file)
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -281,7 +281,7 @@ static inline bool FNAME(is_last_gpte)(struct kvm_mmu *mmu,
         * is not reserved and does not indicate a large page at this level,
         * so clear PT_PAGE_SIZE_MASK in gpte if that is the case.
         */
-       gpte &= level - (PT32_ROOT_LEVEL + mmu->mmu_role.ext.cr4_pse);
+       gpte &= level - (PT32_ROOT_LEVEL + mmu->cpu_role.ext.cr4_pse);
 #endif
        /*
         * PG_LEVEL_4K always terminates.  The RHS has bit 7 set