KVM: x86: Implement Intel PT MSRs read/write emulation
This patch implement Intel Processor Trace MSRs read/write
emulation.
Intel PT MSRs read/write need to be emulated when Intel PT
MSRs is intercepted in guest and during live migration.
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 966abf1..a4ec536 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -140,6 +140,14 @@ module_param_named(preemption_timer, enable_preemption_timer, bool, S_IRUGO);
#define RMODE_GUEST_OWNED_EFLAGS_BITS (~(X86_EFLAGS_IOPL | X86_EFLAGS_VM))
+#define MSR_IA32_RTIT_STATUS_MASK (~(RTIT_STATUS_FILTEREN | \
+ RTIT_STATUS_CONTEXTEN | RTIT_STATUS_TRIGGEREN | \
+ RTIT_STATUS_ERROR | RTIT_STATUS_STOPPED | \
+ RTIT_STATUS_BYTECNT))
+
+#define MSR_IA32_RTIT_OUTPUT_BASE_MASK \
+ (~((1UL << cpuid_query_maxphyaddr(vcpu)) - 1) | 0x7f)
+
/*
* These 2 parameters are used to config the controls for Pause-Loop Exiting:
* ple_gap: upper bound on the amount of time between two successive
@@ -1354,6 +1362,79 @@ void vmx_set_interrupt_shadow(struct kvm_vcpu *vcpu, int mask)
vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, interruptibility);
}
+static int vmx_rtit_ctl_check(struct kvm_vcpu *vcpu, u64 data)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ unsigned long value;
+
+ /*
+ * Any MSR write that attempts to change bits marked reserved will
+ * case a #GP fault.
+ */
+ if (data & vmx->pt_desc.ctl_bitmask)
+ return 1;
+
+ /*
+ * Any attempt to modify IA32_RTIT_CTL while TraceEn is set will
+ * result in a #GP unless the same write also clears TraceEn.
+ */
+ if ((vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) &&
+ ((vmx->pt_desc.guest.ctl ^ data) & ~RTIT_CTL_TRACEEN))
+ return 1;
+
+ /*
+ * WRMSR to IA32_RTIT_CTL that sets TraceEn but clears this bit
+ * and FabricEn would cause #GP, if
+ * CPUID.(EAX=14H, ECX=0):ECX.SNGLRGNOUT[bit 2] = 0
+ */
+ if ((data & RTIT_CTL_TRACEEN) && !(data & RTIT_CTL_TOPA) &&
+ !(data & RTIT_CTL_FABRIC_EN) &&
+ !intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_single_range_output))
+ return 1;
+
+ /*
+ * MTCFreq, CycThresh and PSBFreq encodings check, any MSR write that
+ * utilize encodings marked reserved will casue a #GP fault.
+ */
+ value = intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_mtc_periods);
+ if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_mtc) &&
+ !test_bit((data & RTIT_CTL_MTC_RANGE) >>
+ RTIT_CTL_MTC_RANGE_OFFSET, &value))
+ return 1;
+ value = intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_cycle_thresholds);
+ if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_psb_cyc) &&
+ !test_bit((data & RTIT_CTL_CYC_THRESH) >>
+ RTIT_CTL_CYC_THRESH_OFFSET, &value))
+ return 1;
+ value = intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_psb_periods);
+ if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_psb_cyc) &&
+ !test_bit((data & RTIT_CTL_PSB_FREQ) >>
+ RTIT_CTL_PSB_FREQ_OFFSET, &value))
+ return 1;
+
+ /*
+ * If ADDRx_CFG is reserved or the encodings is >2 will
+ * cause a #GP fault.
+ */
+ value = (data & RTIT_CTL_ADDR0) >> RTIT_CTL_ADDR0_OFFSET;
+ if ((value && (vmx->pt_desc.addr_range < 1)) || (value > 2))
+ return 1;
+ value = (data & RTIT_CTL_ADDR1) >> RTIT_CTL_ADDR1_OFFSET;
+ if ((value && (vmx->pt_desc.addr_range < 2)) || (value > 2))
+ return 1;
+ value = (data & RTIT_CTL_ADDR2) >> RTIT_CTL_ADDR2_OFFSET;
+ if ((value && (vmx->pt_desc.addr_range < 3)) || (value > 2))
+ return 1;
+ value = (data & RTIT_CTL_ADDR3) >> RTIT_CTL_ADDR3_OFFSET;
+ if ((value && (vmx->pt_desc.addr_range < 4)) || (value > 2))
+ return 1;
+
+ return 0;
+}
+
+
static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
{
unsigned long rip;
@@ -1555,6 +1636,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct shared_msr_entry *msr;
+ u32 index;
switch (msr_info->index) {
#ifdef CONFIG_X86_64
@@ -1619,6 +1701,52 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return 1;
msr_info->data = vcpu->arch.ia32_xss;
break;
+ case MSR_IA32_RTIT_CTL:
+ if (pt_mode != PT_MODE_HOST_GUEST)
+ return 1;
+ msr_info->data = vmx->pt_desc.guest.ctl;
+ break;
+ case MSR_IA32_RTIT_STATUS:
+ if (pt_mode != PT_MODE_HOST_GUEST)
+ return 1;
+ msr_info->data = vmx->pt_desc.guest.status;
+ break;
+ case MSR_IA32_RTIT_CR3_MATCH:
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ !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 ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (!intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_topa_output) &&
+ !intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_single_range_output)))
+ return 1;
+ msr_info->data = vmx->pt_desc.guest.output_base;
+ break;
+ case MSR_IA32_RTIT_OUTPUT_MASK:
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (!intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_topa_output) &&
+ !intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_single_range_output)))
+ return 1;
+ msr_info->data = vmx->pt_desc.guest.output_mask;
+ break;
+ case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B:
+ index = msr_info->index - MSR_IA32_RTIT_ADDR0_A;
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (index >= 2 * intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_num_address_ranges)))
+ return 1;
+ if (index % 2)
+ msr_info->data = vmx->pt_desc.guest.addr_b[index / 2];
+ else
+ msr_info->data = vmx->pt_desc.guest.addr_a[index / 2];
+ break;
case MSR_TSC_AUX:
if (!msr_info->host_initiated &&
!guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))
@@ -1648,6 +1776,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
int ret = 0;
u32 msr_index = msr_info->index;
u64 data = msr_info->data;
+ u32 index;
switch (msr_index) {
case MSR_EFER:
@@ -1799,6 +1928,61 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
else
clear_atomic_switch_msr(vmx, MSR_IA32_XSS);
break;
+ case MSR_IA32_RTIT_CTL:
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ vmx_rtit_ctl_check(vcpu, data))
+ return 1;
+ vmcs_write64(GUEST_IA32_RTIT_CTL, data);
+ vmx->pt_desc.guest.ctl = data;
+ break;
+ case MSR_IA32_RTIT_STATUS:
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
+ (data & MSR_IA32_RTIT_STATUS_MASK))
+ return 1;
+ vmx->pt_desc.guest.status = data;
+ break;
+ case MSR_IA32_RTIT_CR3_MATCH:
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
+ !intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_cr3_filtering))
+ return 1;
+ vmx->pt_desc.guest.cr3_match = data;
+ break;
+ case MSR_IA32_RTIT_OUTPUT_BASE:
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
+ (!intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_topa_output) &&
+ !intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_single_range_output)) ||
+ (data & MSR_IA32_RTIT_OUTPUT_BASE_MASK))
+ return 1;
+ vmx->pt_desc.guest.output_base = data;
+ break;
+ case MSR_IA32_RTIT_OUTPUT_MASK:
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
+ (!intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_topa_output) &&
+ !intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_single_range_output)))
+ return 1;
+ vmx->pt_desc.guest.output_mask = data;
+ break;
+ case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B:
+ index = msr_info->index - MSR_IA32_RTIT_ADDR0_A;
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
+ (index >= 2 * intel_pt_validate_cap(vmx->pt_desc.caps,
+ PT_CAP_num_address_ranges)))
+ return 1;
+ if (index % 2)
+ vmx->pt_desc.guest.addr_b[index / 2] = data;
+ else
+ vmx->pt_desc.guest.addr_a[index / 2] = data;
+ break;
case MSR_TSC_AUX:
if (!msr_info->host_initiated &&
!guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))