| Message ID | 20241001050110.3643764-6-xin@zytor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Enable FRED with KVM VMX | expand |
On Mon, Sep 30, 2024 at 10:00:48PM -0700, Xin Li (Intel) wrote: >From: Xin Li <xin3.li@intel.com> > >Do not virtualize FRED if FRED consistency checks fail. > >Either on broken hardware, or when run KVM on top of another hypervisor >before the underlying hypervisor implements nested FRED correctly. > >Suggested-by: Chao Gao <chao.gao@intel.com> >Signed-off-by: Xin Li <xin3.li@intel.com> >Signed-off-by: Xin Li (Intel) <xin@zytor.com> >Tested-by: Shan Kang <shan.kang@intel.com> Reviewed-by: Chao Gao <chao.gao@intel.com> one nit below, >--- > arch/x86/kvm/vmx/capabilities.h | 7 +++++++ > arch/x86/kvm/vmx/vmx.c | 3 +++ > 2 files changed, 10 insertions(+) > >diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h >index e8f3ad0f79ee..2962a3bb9747 100644 >--- a/arch/x86/kvm/vmx/capabilities.h >+++ b/arch/x86/kvm/vmx/capabilities.h >@@ -400,6 +400,13 @@ static inline bool vmx_pebs_supported(void) > return boot_cpu_has(X86_FEATURE_PEBS) && kvm_pmu_cap.pebs_ept; > } > >+static inline bool cpu_has_vmx_fred(void) >+{ >+ /* No need to check FRED VM exit controls. */ how about: /* * setup_vmcs_config() guarantees FRED VM-entry/exit controls are * either all set or none. So, no need to check FRED VM-exit controls. */ It is better to call out the reason. >+ return boot_cpu_has(X86_FEATURE_FRED) && >+ (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_FRED); >+} >+
On 10/22/2024 1:48 AM, Chao Gao wrote: > On Mon, Sep 30, 2024 at 10:00:48PM -0700, Xin Li (Intel) wrote: >> From: Xin Li <xin3.li@intel.com> >> >> Do not virtualize FRED if FRED consistency checks fail. >> >> Either on broken hardware, or when run KVM on top of another hypervisor >> before the underlying hypervisor implements nested FRED correctly. >> >> Suggested-by: Chao Gao <chao.gao@intel.com> >> Signed-off-by: Xin Li <xin3.li@intel.com> >> Signed-off-by: Xin Li (Intel) <xin@zytor.com> >> Tested-by: Shan Kang <shan.kang@intel.com> > > Reviewed-by: Chao Gao <chao.gao@intel.com> > > one nit below, > >> --- >> arch/x86/kvm/vmx/capabilities.h | 7 +++++++ >> arch/x86/kvm/vmx/vmx.c | 3 +++ >> 2 files changed, 10 insertions(+) >> >> diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h >> index e8f3ad0f79ee..2962a3bb9747 100644 >> --- a/arch/x86/kvm/vmx/capabilities.h >> +++ b/arch/x86/kvm/vmx/capabilities.h >> @@ -400,6 +400,13 @@ static inline bool vmx_pebs_supported(void) >> return boot_cpu_has(X86_FEATURE_PEBS) && kvm_pmu_cap.pebs_ept; >> } >> >> +static inline bool cpu_has_vmx_fred(void) >> +{ >> + /* No need to check FRED VM exit controls. */ > > how about: > > /* > * setup_vmcs_config() guarantees FRED VM-entry/exit controls are > * either all set or none. So, no need to check FRED VM-exit controls. > */ > > It is better to call out the reason. > make sense!
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h index e8f3ad0f79ee..2962a3bb9747 100644 --- a/arch/x86/kvm/vmx/capabilities.h +++ b/arch/x86/kvm/vmx/capabilities.h @@ -400,6 +400,13 @@ static inline bool vmx_pebs_supported(void) return boot_cpu_has(X86_FEATURE_PEBS) && kvm_pmu_cap.pebs_ept; } +static inline bool cpu_has_vmx_fred(void) +{ + /* No need to check FRED VM exit controls. */ + return boot_cpu_has(X86_FEATURE_FRED) && + (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_FRED); +} + static inline bool cpu_has_notify_vmexit(void) { return vmcs_config.cpu_based_2nd_exec_ctrl & diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index efd2ad397ad2..9b4c30db911f 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -8001,6 +8001,9 @@ static __init void vmx_set_cpu_caps(void) kvm_cpu_cap_check_and_set(X86_FEATURE_DTES64); } + if (!cpu_has_vmx_fred()) + kvm_cpu_cap_clear(X86_FEATURE_FRED); + if (!enable_pmu) kvm_cpu_cap_clear(X86_FEATURE_PDCM); kvm_caps.supported_perf_cap = vmx_get_perf_capabilities();