From: Yang Weijiang <weijiang.yang@intel.com>
To: pbonzini@redhat.com, kvm@vger.kernel.org, mst@redhat.com,
rkrcmar@redhat.com, jmattson@google.com,
linux-kernel@vger.kernel.org, yu-cheng.yu@intel.com
Cc: Yang Weijiang <weijiang.yang@intel.com>,
Zhang Yi Z <yi.z.zhang@linux.intel.com>
Subject: [RFC PATCH v4 6/8] KVM:x86: Allow Guest to set supported bits in XSS
Date: Mon, 18 Mar 2019 23:03:49 +0800 [thread overview]
Message-ID: <20190318150351.15550-7-weijiang.yang@intel.com> (raw)
In-Reply-To: <20190318150351.15550-1-weijiang.yang@intel.com>
Now that KVM supports setting CET related bits.
Previously, KVM did not support setting any bits in XSS
and so hardcoded its check to inject a #GP if Guest
attempted to write a non-zero value to IA32_XSS.
Signed-off-by: Zhang Yi Z <yi.z.zhang@linux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/cpuid.c | 13 ++++++++++---
arch/x86/kvm/vmx.c | 7 ++-----
3 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index fc038bf1924a..30dfb5a65d1b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -616,6 +616,7 @@ struct kvm_vcpu_arch {
u64 xcr0;
u64 guest_supported_xcr0;
+ u64 guest_supported_xss;
u32 guest_xstate_size;
struct kvm_pio_request pio;
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 29d6a5cdc746..e66a0557899c 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -125,9 +125,16 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
}
best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
- if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
- best->ebx = xstate_required_size(vcpu->arch.xcr0 |
- kvm_supported_xss(), true);
+ if (best) {
+ if (best->eax & (F(XSAVES) | F(XSAVEC)))
+ best->ebx = xstate_required_size(vcpu->arch.xcr0 |
+ kvm_supported_xss(), true);
+
+ vcpu->arch.guest_supported_xss = best->ecx &
+ kvm_supported_xss();
+ } else {
+ vcpu->arch.guest_supported_xss = 0;
+ }
/*
* The existing code assumes virtual address is 48-bit or 57-bit in the
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 246467c12930..816e11a66557 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4327,12 +4327,9 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_IA32_XSS:
if (!vmx_xsaves_supported())
return 1;
- /*
- * The only supported bit as of Skylake is bit 8, but
- * it is not supported on KVM.
- */
- if (data != 0)
+ if (data & ~vcpu->arch.guest_supported_xss)
return 1;
+
vcpu->arch.ia32_xss = data;
if (vcpu->arch.ia32_xss != host_xss)
add_atomic_switch_msr(vmx, MSR_IA32_XSS,
--
2.17.1
next prev parent reply other threads:[~2019-03-19 8:14 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-18 15:03 [RFC PATCH v4 0/8] This patch-set is to enable Guest CET support Yang Weijiang
2019-03-18 15:03 ` [RFC PATCH v4 1/8] KVM:VMX: Define CET VMCS fields and bits Yang Weijiang
2019-04-02 19:57 ` Sean Christopherson
2019-03-18 15:03 ` [RFC PATCH v4 2/8] KVM:CPUID: Add CET CPUID support for Guest Yang Weijiang
2019-04-02 20:21 ` Sean Christopherson
2019-04-02 20:40 ` Sean Christopherson
2019-03-18 15:03 ` [RFC PATCH v4 3/8] KVM:CPUID: Fix xsaves area size calculation for CPUID.(EAX=0xD,ECX=1) Yang Weijiang
2019-04-02 20:27 ` Sean Christopherson
2019-03-18 15:03 ` [RFC PATCH v4 4/8] KVM:VMX: Pass through host CET related MSRs to Guest Yang Weijiang
2019-04-02 20:27 ` Sean Christopherson
2019-04-02 20:46 ` Yang Weijiang
2019-03-18 15:03 ` [RFC PATCH v4 5/8] KVM:VMX: Load Guest CET via VMCS when CET is enabled in Guest Yang Weijiang
2019-04-02 20:30 ` Sean Christopherson
2019-03-18 15:03 ` Yang Weijiang [this message]
2019-03-18 15:03 ` [RFC PATCH v4 7/8] KVM:x86: load guest fpu state when accessing MSRs managed by XSAVES Yang Weijiang
2019-04-02 20:39 ` Sean Christopherson
2019-03-18 15:03 ` [RFC PATCH v4 8/8] KVM:x86: Add user-space read/write interface for CET MSRs Yang Weijiang
2019-04-02 20:35 ` Sean Christopherson
2019-03-25 20:45 ` [RFC PATCH v4 0/8] This patch-set is to enable Guest CET support Yang Weijiang
2019-03-26 22:31 ` Sean Christopherson
2019-04-02 20:10 ` Sean Christopherson
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