diff options
Diffstat (limited to 'arch/x86/kvm/svm/sev.c')
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 1512bacd74a9..3517d6736c93 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -23,6 +23,7 @@ #include <asm/pkru.h> #include <asm/trapnr.h> #include <asm/fpu/xcr.h> +#include <asm/fpu/xstate.h> #include <asm/debugreg.h> #include "mmu.h" @@ -584,6 +585,10 @@ static int sev_es_sync_vmsa(struct vcpu_svm *svm) struct kvm_vcpu *vcpu = &svm->vcpu; struct kvm_sev_info *sev = &to_kvm_svm(vcpu->kvm)->sev_info; struct sev_es_save_area *save = svm->sev_es.vmsa; + struct xregs_state *xsave; + const u8 *s; + u8 *d; + int i; /* Check some debug related fields before encrypting the VMSA */ if (svm->vcpu.guest_debug || (svm->vmcb->save.dr7 & ~DR7_FIXED_1)) @@ -626,6 +631,44 @@ static int sev_es_sync_vmsa(struct vcpu_svm *svm) save->sev_features = sev->vmsa_features; + /* + * Skip FPU and AVX setup with KVM_SEV_ES_INIT to avoid + * breaking older measurements. + */ + if (vcpu->kvm->arch.vm_type != KVM_X86_DEFAULT_VM) { + xsave = &vcpu->arch.guest_fpu.fpstate->regs.xsave; + save->x87_dp = xsave->i387.rdp; + save->mxcsr = xsave->i387.mxcsr; + save->x87_ftw = xsave->i387.twd; + save->x87_fsw = xsave->i387.swd; + save->x87_fcw = xsave->i387.cwd; + save->x87_fop = xsave->i387.fop; + save->x87_ds = 0; + save->x87_cs = 0; + save->x87_rip = xsave->i387.rip; + + for (i = 0; i < 8; i++) { + /* + * The format of the x87 save area is undocumented and + * definitely not what you would expect. It consists of + * an 8*8 bytes area with bytes 0-7, and an 8*2 bytes + * area with bytes 8-9 of each register. + */ + d = save->fpreg_x87 + i * 8; + s = ((u8 *)xsave->i387.st_space) + i * 16; + memcpy(d, s, 8); + save->fpreg_x87[64 + i * 2] = s[8]; + save->fpreg_x87[64 + i * 2 + 1] = s[9]; + } + memcpy(save->fpreg_xmm, xsave->i387.xmm_space, 256); + + s = get_xsave_addr(xsave, XFEATURE_YMM); + if (s) + memcpy(save->fpreg_ymm, s, 256); + else + memset(save->fpreg_ymm, 0, 256); + } + pr_debug("Virtual Machine Save Area (VMSA):\n"); print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, save, sizeof(*save), false); @@ -664,6 +707,13 @@ static int __sev_launch_update_vmsa(struct kvm *kvm, struct kvm_vcpu *vcpu, if (ret) return ret; + /* + * SEV-ES guests maintain an encrypted version of their FPU + * state which is restored and saved on VMRUN and VMEXIT. + * Mark vcpu->arch.guest_fpu->fpstate as scratch so it won't + * do xsave/xrstor on it. + */ + fpstate_set_confidential(&vcpu->arch.guest_fpu); vcpu->arch.guest_state_protected = true; return 0; } |