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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-04-28 16:10:24 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-05-15 12:26:16 -0400 |
| commit | 2408500dfc8f275f9057586b81466989f0fafc59 (patch) | |
| tree | 0cd76e0599e6c7b579a6a7df969d724bd156fb46 | |
| parent | 551896e0e060ca32947621e353b4918e90b88822 (diff) | |
| download | linux-2408500dfc8f275f9057586b81466989f0fafc59.tar.bz2 | |
KVM: nVMX: Truncate writes to vmcs.SYSENTER_EIP/ESP for 32-bit vCPU
Explicitly truncate the data written to vmcs.SYSENTER_EIP/ESP on WRMSR
if the virtual CPU doesn't support 64-bit mode. The SYSENTER address
fields in the VMCS are natural width, i.e. bits 63:32 are dropped if the
CPU doesn't support Intel 64 architectures. This behavior is visible to
the guest after a VM-Exit/VM-Exit roundtrip, e.g. if the guest sets bits
63:32 in the actual MSR.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200428231025.12766-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 9ce182db7326..fc2b660aea7d 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1943,6 +1943,16 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return 0; } +static u64 nested_vmx_truncate_sysenter_addr(struct kvm_vcpu *vcpu, + u64 data) +{ +#ifdef CONFIG_X86_64 + if (!guest_cpuid_has(vcpu, X86_FEATURE_LM)) + return (u32)data; +#endif + return (unsigned long)data; +} + /* * Writes msr value into the appropriate "register". * Returns 0 on success, non-0 otherwise. @@ -1980,13 +1990,17 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vmcs_write32(GUEST_SYSENTER_CS, data); break; case MSR_IA32_SYSENTER_EIP: - if (is_guest_mode(vcpu)) + if (is_guest_mode(vcpu)) { + data = nested_vmx_truncate_sysenter_addr(vcpu, data); get_vmcs12(vcpu)->guest_sysenter_eip = data; + } vmcs_writel(GUEST_SYSENTER_EIP, data); break; case MSR_IA32_SYSENTER_ESP: - if (is_guest_mode(vcpu)) + if (is_guest_mode(vcpu)) { + data = nested_vmx_truncate_sysenter_addr(vcpu, data); get_vmcs12(vcpu)->guest_sysenter_esp = data; + } vmcs_writel(GUEST_SYSENTER_ESP, data); break; case MSR_IA32_DEBUGCTLMSR: |