| Message ID | 20210827070249.924633-6-xiaoyao.li@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: VMX: PT (processor trace) optimization cleanup and fixes | expand |
On 27/08/21 09:02, Xiaoyao Li wrote: > Per SDM, it triggers #GP for all the accessing of PT MSRs, if > X86_FEATURE_INTEL_PT is not available. > > Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> > --- > Changes in v2: > - allow userspace/host access regradless of PT bit, (Sean) > --- > arch/x86/kvm/vmx/vmx.c | 38 +++++++++++++++++++++++++------------- > 1 file changed, 25 insertions(+), 13 deletions(-) Let's cache this in vmx->pt_desc. More precisely: - always call update_intel_pt_cfg from vmx_vcpu_after_set_cpuid - add a field vmx->pt_desc.available matching guest_cpuid_has(vcpu, X86_FEATURE_INTEL_PT) - if it is false, clear _all_ of vmx->pt_desc (with memcpy) and return early from update_intel_pt_cfg Thanks, Paolo > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index b9d640029c40..394ef4732838 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -1007,10 +1007,21 @@ static unsigned long segment_base(u16 selector) > } > #endif > > -static inline bool pt_can_write_msr(struct vcpu_vmx *vmx) > +static inline bool pt_can_write_msr(struct vcpu_vmx *vmx, > + struct msr_data *msr_info) > { > return vmx_pt_mode_is_host_guest() && > - !(vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN); > + !(vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) && > + (msr_info->host_initiated || > + guest_cpuid_has(&vmx->vcpu, X86_FEATURE_INTEL_PT)); > +} > + > +static inline bool pt_can_read_msr(struct kvm_vcpu *vcpu, > + struct msr_data *msr_info) > +{ > + return vmx_pt_mode_is_host_guest() && > + (msr_info->host_initiated || > + guest_cpuid_has(vcpu, X86_FEATURE_INTEL_PT)); > } > > static inline bool pt_output_base_valid(struct kvm_vcpu *vcpu, u64 base) > @@ -1852,24 +1863,24 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > &msr_info->data); > break; > case MSR_IA32_RTIT_CTL: > - if (!vmx_pt_mode_is_host_guest()) > + if (!pt_can_read_msr(vcpu, msr_info)) > return 1; > msr_info->data = vmx->pt_desc.guest.ctl; > break; > case MSR_IA32_RTIT_STATUS: > - if (!vmx_pt_mode_is_host_guest()) > + if (!pt_can_read_msr(vcpu, msr_info)) > return 1; > msr_info->data = vmx->pt_desc.guest.status; > break; > case MSR_IA32_RTIT_CR3_MATCH: > - if (!vmx_pt_mode_is_host_guest() || > + if (!pt_can_read_msr(vcpu, msr_info) || > !intel_pt_validate_cap(vmx->pt_desc.caps, > PT_CAP_cr3_filtering)) > return 1; > msr_info->data = vmx->pt_desc.guest.cr3_match; > break; > case MSR_IA32_RTIT_OUTPUT_BASE: > - if (!vmx_pt_mode_is_host_guest() || > + if (!pt_can_read_msr(vcpu, msr_info) || > (!intel_pt_validate_cap(vmx->pt_desc.caps, > PT_CAP_topa_output) && > !intel_pt_validate_cap(vmx->pt_desc.caps, > @@ -1878,7 +1889,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > msr_info->data = vmx->pt_desc.guest.output_base; > break; > case MSR_IA32_RTIT_OUTPUT_MASK: > - if (!vmx_pt_mode_is_host_guest() || > + if (!pt_can_read_msr(vcpu, msr_info) || > (!intel_pt_validate_cap(vmx->pt_desc.caps, > PT_CAP_topa_output) && > !intel_pt_validate_cap(vmx->pt_desc.caps, > @@ -1888,7 +1899,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > break; > case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B: > index = msr_info->index - MSR_IA32_RTIT_ADDR0_A; > - if (!vmx_pt_mode_is_host_guest() || > + if (!pt_can_read_msr(vcpu, msr_info) || > (index >= 2 * vmx->pt_desc.nr_addr_ranges)) > return 1; > if (index % 2) > @@ -2156,6 +2167,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > return vmx_set_vmx_msr(vcpu, msr_index, data); > case MSR_IA32_RTIT_CTL: > if (!vmx_pt_mode_is_host_guest() || > + !guest_cpuid_has(vcpu, X86_FEATURE_INTEL_PT) || > vmx_rtit_ctl_check(vcpu, data) || > vmx->nested.vmxon) > return 1; > @@ -2164,14 +2176,14 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > pt_update_intercept_for_msr(vcpu); > break; > case MSR_IA32_RTIT_STATUS: > - if (!pt_can_write_msr(vmx)) > + if (!pt_can_write_msr(vmx, msr_info)) > return 1; > if (data & MSR_IA32_RTIT_STATUS_MASK) > return 1; > vmx->pt_desc.guest.status = data; > break; > case MSR_IA32_RTIT_CR3_MATCH: > - if (!pt_can_write_msr(vmx)) > + if (!pt_can_write_msr(vmx, msr_info)) > return 1; > if (!intel_pt_validate_cap(vmx->pt_desc.caps, > PT_CAP_cr3_filtering)) > @@ -2179,7 +2191,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > vmx->pt_desc.guest.cr3_match = data; > break; > case MSR_IA32_RTIT_OUTPUT_BASE: > - if (!pt_can_write_msr(vmx)) > + if (!pt_can_write_msr(vmx, msr_info)) > return 1; > if (!intel_pt_validate_cap(vmx->pt_desc.caps, > PT_CAP_topa_output) && > @@ -2191,7 +2203,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > vmx->pt_desc.guest.output_base = data; > break; > case MSR_IA32_RTIT_OUTPUT_MASK: > - if (!pt_can_write_msr(vmx)) > + if (!pt_can_write_msr(vmx, msr_info)) > return 1; > if (!intel_pt_validate_cap(vmx->pt_desc.caps, > PT_CAP_topa_output) && > @@ -2201,7 +2213,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > vmx->pt_desc.guest.output_mask = data; > break; > case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B: > - if (!pt_can_write_msr(vmx)) > + if (!pt_can_write_msr(vmx, msr_info)) > return 1; > index = msr_info->index - MSR_IA32_RTIT_ADDR0_A; > if (index >= 2 * vmx->pt_desc.nr_addr_ranges) >
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index b9d640029c40..394ef4732838 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1007,10 +1007,21 @@ static unsigned long segment_base(u16 selector) } #endif -static inline bool pt_can_write_msr(struct vcpu_vmx *vmx) +static inline bool pt_can_write_msr(struct vcpu_vmx *vmx, + struct msr_data *msr_info) { return vmx_pt_mode_is_host_guest() && - !(vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN); + !(vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) && + (msr_info->host_initiated || + guest_cpuid_has(&vmx->vcpu, X86_FEATURE_INTEL_PT)); +} + +static inline bool pt_can_read_msr(struct kvm_vcpu *vcpu, + struct msr_data *msr_info) +{ + return vmx_pt_mode_is_host_guest() && + (msr_info->host_initiated || + guest_cpuid_has(vcpu, X86_FEATURE_INTEL_PT)); } static inline bool pt_output_base_valid(struct kvm_vcpu *vcpu, u64 base) @@ -1852,24 +1863,24 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) &msr_info->data); break; case MSR_IA32_RTIT_CTL: - if (!vmx_pt_mode_is_host_guest()) + if (!pt_can_read_msr(vcpu, msr_info)) return 1; msr_info->data = vmx->pt_desc.guest.ctl; break; case MSR_IA32_RTIT_STATUS: - if (!vmx_pt_mode_is_host_guest()) + if (!pt_can_read_msr(vcpu, msr_info)) return 1; msr_info->data = vmx->pt_desc.guest.status; break; case MSR_IA32_RTIT_CR3_MATCH: - if (!vmx_pt_mode_is_host_guest() || + if (!pt_can_read_msr(vcpu, msr_info) || !intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_cr3_filtering)) return 1; msr_info->data = vmx->pt_desc.guest.cr3_match; break; case MSR_IA32_RTIT_OUTPUT_BASE: - if (!vmx_pt_mode_is_host_guest() || + if (!pt_can_read_msr(vcpu, msr_info) || (!intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_topa_output) && !intel_pt_validate_cap(vmx->pt_desc.caps, @@ -1878,7 +1889,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = vmx->pt_desc.guest.output_base; break; case MSR_IA32_RTIT_OUTPUT_MASK: - if (!vmx_pt_mode_is_host_guest() || + if (!pt_can_read_msr(vcpu, msr_info) || (!intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_topa_output) && !intel_pt_validate_cap(vmx->pt_desc.caps, @@ -1888,7 +1899,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B: index = msr_info->index - MSR_IA32_RTIT_ADDR0_A; - if (!vmx_pt_mode_is_host_guest() || + if (!pt_can_read_msr(vcpu, msr_info) || (index >= 2 * vmx->pt_desc.nr_addr_ranges)) return 1; if (index % 2) @@ -2156,6 +2167,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return vmx_set_vmx_msr(vcpu, msr_index, data); case MSR_IA32_RTIT_CTL: if (!vmx_pt_mode_is_host_guest() || + !guest_cpuid_has(vcpu, X86_FEATURE_INTEL_PT) || vmx_rtit_ctl_check(vcpu, data) || vmx->nested.vmxon) return 1; @@ -2164,14 +2176,14 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) pt_update_intercept_for_msr(vcpu); break; case MSR_IA32_RTIT_STATUS: - if (!pt_can_write_msr(vmx)) + if (!pt_can_write_msr(vmx, msr_info)) return 1; if (data & MSR_IA32_RTIT_STATUS_MASK) return 1; vmx->pt_desc.guest.status = data; break; case MSR_IA32_RTIT_CR3_MATCH: - if (!pt_can_write_msr(vmx)) + if (!pt_can_write_msr(vmx, msr_info)) return 1; if (!intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_cr3_filtering)) @@ -2179,7 +2191,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vmx->pt_desc.guest.cr3_match = data; break; case MSR_IA32_RTIT_OUTPUT_BASE: - if (!pt_can_write_msr(vmx)) + if (!pt_can_write_msr(vmx, msr_info)) return 1; if (!intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_topa_output) && @@ -2191,7 +2203,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vmx->pt_desc.guest.output_base = data; break; case MSR_IA32_RTIT_OUTPUT_MASK: - if (!pt_can_write_msr(vmx)) + if (!pt_can_write_msr(vmx, msr_info)) return 1; if (!intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_topa_output) && @@ -2201,7 +2213,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) vmx->pt_desc.guest.output_mask = data; break; case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B: - if (!pt_can_write_msr(vmx)) + if (!pt_can_write_msr(vmx, msr_info)) return 1; index = msr_info->index - MSR_IA32_RTIT_ADDR0_A; if (index >= 2 * vmx->pt_desc.nr_addr_ranges)
Per SDM, it triggers #GP for all the accessing of PT MSRs, if X86_FEATURE_INTEL_PT is not available. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> --- Changes in v2: - allow userspace/host access regradless of PT bit, (Sean) --- arch/x86/kvm/vmx/vmx.c | 38 +++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-)