Commit Message
Isaku Yamahata
Oct. 30, 2022, 6:23 a.m. UTC
From: Isaku Yamahata <isaku.yamahata@intel.com> On exiting from the guest TD, xsave state is clobbered. Restore xsave state on TD exit. Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> --- arch/x86/kvm/vmx/tdx.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 021040fdd630..3ec465cbaeef 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -2,6 +2,7 @@ #include <linux/cpu.h> #include <linux/mmu_context.h> +#include <asm/fpu/xcr.h> #include <asm/tdx.h> #include "capabilities.h" @@ -455,6 +456,22 @@ void tdx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) vcpu->kvm->vm_bugged = true; } +static void tdx_restore_host_xsave_state(struct kvm_vcpu *vcpu) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm); + + if (static_cpu_has(X86_FEATURE_XSAVE) && + host_xcr0 != (kvm_tdx->xfam & kvm_caps.supported_xcr0)) + xsetbv(XCR_XFEATURE_ENABLED_MASK, host_xcr0); + if (static_cpu_has(X86_FEATURE_XSAVES) && + /* PT can be exposed to TD guest regardless of KVM's XSS support */ + host_xss != (kvm_tdx->xfam & (kvm_caps.supported_xss | XFEATURE_MASK_PT))) + wrmsrl(MSR_IA32_XSS, host_xss); + if (static_cpu_has(X86_FEATURE_PKU) && + (kvm_tdx->xfam & XFEATURE_MASK_PKRU)) + write_pkru(vcpu->arch.host_pkru); +} + u64 __tdx_vcpu_run(hpa_t tdvpr, void *regs, u32 regs_mask); static noinstr void tdx_vcpu_enter_exit(struct kvm_vcpu *vcpu, @@ -478,6 +495,7 @@ fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu) tdx_vcpu_enter_exit(vcpu, tdx); + tdx_restore_host_xsave_state(vcpu); tdx->host_state_need_restore = true; vcpu->arch.regs_avail &= ~VMX_REGS_LAZY_LOAD_SET;