| Message ID | a3d79d60eb1ed8c15b69f351a6ffd5addd62a3a1.1375638539.git.jan.kiszka@web.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Aug 5, 2013 at 1:49 AM, Jan Kiszka <jan.kiszka@web.de> wrote: > From: Jan Kiszka <jan.kiszka@siemens.com> > > Implement and advertise VM_EXIT_SAVE_IA32_EFER. L0 traps EFER writes > unconditionally, so we always find the current L2 value in the > architectural state. > > Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> > --- > arch/x86/kvm/vmx.c | 4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 84a05b4..7208d0b 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -2203,7 +2203,7 @@ static __init void nested_vmx_setup_ctls_msrs(void) > nested_vmx_exit_ctls_high = 0; > #endif > nested_vmx_exit_ctls_high |= (VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR | > - VM_EXIT_LOAD_IA32_EFER); > + VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER); Here you may need to access MSR_IA32_VMX_EXIT_CTLS first to check if host support these two features. The codes for "entry controls" following it can achieve goals like this. Arthur > > /* entry controls */ > rdmsr(MSR_IA32_VMX_ENTRY_CTLS, > @@ -8113,6 +8113,8 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) > vmcs12->guest_ia32_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL); > if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_PAT) > vmcs12->guest_ia32_pat = vmcs_read64(GUEST_IA32_PAT); > + if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_EFER) > + vmcs12->guest_ia32_efer = vcpu->arch.efer; > vmcs12->guest_sysenter_cs = vmcs_read32(GUEST_SYSENTER_CS); > vmcs12->guest_sysenter_esp = vmcs_readl(GUEST_SYSENTER_ESP); > vmcs12->guest_sysenter_eip = vmcs_readl(GUEST_SYSENTER_EIP); > -- > 1.7.3.4 > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2013-08-05 09:21, Arthur Chunqi Li wrote: > On Mon, Aug 5, 2013 at 1:49 AM, Jan Kiszka <jan.kiszka@web.de> wrote: >> From: Jan Kiszka <jan.kiszka@siemens.com> >> >> Implement and advertise VM_EXIT_SAVE_IA32_EFER. L0 traps EFER writes >> unconditionally, so we always find the current L2 value in the >> architectural state. >> >> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> >> --- >> arch/x86/kvm/vmx.c | 4 +++- >> 1 files changed, 3 insertions(+), 1 deletions(-) >> >> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c >> index 84a05b4..7208d0b 100644 >> --- a/arch/x86/kvm/vmx.c >> +++ b/arch/x86/kvm/vmx.c >> @@ -2203,7 +2203,7 @@ static __init void nested_vmx_setup_ctls_msrs(void) >> nested_vmx_exit_ctls_high = 0; >> #endif >> nested_vmx_exit_ctls_high |= (VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR | >> - VM_EXIT_LOAD_IA32_EFER); >> + VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER); > Here you may need to access MSR_IA32_VMX_EXIT_CTLS first to check if > host support these two features. The codes for "entry controls" > following it can achieve goals like this. We are providing this feature independently of the host's support. Every write to EFER is trapped by L0, so we can emulate saving by reading what L0 recorded. Jan
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 84a05b4..7208d0b 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2203,7 +2203,7 @@ static __init void nested_vmx_setup_ctls_msrs(void) nested_vmx_exit_ctls_high = 0; #endif nested_vmx_exit_ctls_high |= (VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR | - VM_EXIT_LOAD_IA32_EFER); + VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER); /* entry controls */ rdmsr(MSR_IA32_VMX_ENTRY_CTLS, @@ -8113,6 +8113,8 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) vmcs12->guest_ia32_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL); if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_PAT) vmcs12->guest_ia32_pat = vmcs_read64(GUEST_IA32_PAT); + if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_EFER) + vmcs12->guest_ia32_efer = vcpu->arch.efer; vmcs12->guest_sysenter_cs = vmcs_read32(GUEST_SYSENTER_CS); vmcs12->guest_sysenter_esp = vmcs_readl(GUEST_SYSENTER_ESP); vmcs12->guest_sysenter_eip = vmcs_readl(GUEST_SYSENTER_EIP);