x86/kvm: Add KVM-specific VMMCALL handling under SEV-ES

Implement the callbacks to copy the processor state required by KVM to
the GHCB.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
[ jroedel@suse.de: - Split out of a larger patch
                   - Adapt to different callback functions ]
Co-developed-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-64-joro@8bytes.org

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 08320b0..0f95972 100644 (file)
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -36,6 +36,8 @@
 #include <asm/hypervisor.h>
 #include <asm/tlb.h>
 #include <asm/cpuidle_haltpoll.h>
+#include <asm/ptrace.h>
+#include <asm/svm.h>
 
 DEFINE_STATIC_KEY_FALSE(kvm_async_pf_enabled);
 
@@ -746,13 +748,34 @@ static void __init kvm_init_platform(void)
        x86_platform.apic_post_init = kvm_apic_init;
 }
 
+#if defined(CONFIG_AMD_MEM_ENCRYPT)
+static void kvm_sev_es_hcall_prepare(struct ghcb *ghcb, struct pt_regs *regs)
+{
+       /* RAX and CPL are already in the GHCB */
+       ghcb_set_rbx(ghcb, regs->bx);
+       ghcb_set_rcx(ghcb, regs->cx);
+       ghcb_set_rdx(ghcb, regs->dx);
+       ghcb_set_rsi(ghcb, regs->si);
+}
+
+static bool kvm_sev_es_hcall_finish(struct ghcb *ghcb, struct pt_regs *regs)
+{
+       /* No checking of the return state needed */
+       return true;
+}
+#endif
+
 const __initconst struct hypervisor_x86 x86_hyper_kvm = {
-       .name                   = "KVM",
-       .detect                 = kvm_detect,
-       .type                   = X86_HYPER_KVM,
-       .init.guest_late_init   = kvm_guest_init,
-       .init.x2apic_available  = kvm_para_available,
-       .init.init_platform     = kvm_init_platform,
+       .name                           = "KVM",
+       .detect                         = kvm_detect,
+       .type                           = X86_HYPER_KVM,
+       .init.guest_late_init           = kvm_guest_init,
+       .init.x2apic_available          = kvm_para_available,
+       .init.init_platform             = kvm_init_platform,
+#if defined(CONFIG_AMD_MEM_ENCRYPT)
+       .runtime.sev_es_hcall_prepare   = kvm_sev_es_hcall_prepare,
+       .runtime.sev_es_hcall_finish    = kvm_sev_es_hcall_finish,
+#endif
 };
 
 static __init int activate_jump_labels(void)