[PATCH v7 11/13] KVM: x86: Implement Intel Processor Trace MSRs read/write

Luwei Kang
2018-05-03T12:13:26Z

From: Chao Peng <chao.p.peng@linux.intel.com>

Implement Intel Processor Trace MSRs read/write.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Signed-off-by: Luwei Kang <luwei.kang@intel.com>
---
arch/x86/include/asm/intel_pt.h | 8 ++
arch/x86/kvm/vmx.c | 163 ++++++++++++++++++++++++++++++++++++++++
arch/x86/kvm/x86.c | 33 +++++++-
3 files changed, 203 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/intel_pt.h b/arch/x86/include/asm/intel_pt.h
index 43ad260..dc0f3f0 100644
--- a/arch/x86/include/asm/intel_pt.h
+++ b/arch/x86/include/asm/intel_pt.h
@@ -5,6 +5,14 @@
#define PT_CPUID_LEAVES 2
#define PT_CPUID_REGS_NUM 4 /* number of regsters (eax, ebx, ecx, edx) */

+#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)
+
enum pt_mode {
PT_MODE_SYSTEM = 0,
PT_MODE_HOST,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3ed02a8..2a29ab9 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2769,6 +2769,77 @@ static 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) &&
+ !__pt_cap_get(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 = __pt_cap_get(vmx->pt_desc.caps, PT_CAP_mtc_periods);
+ if (__pt_cap_get(vmx->pt_desc.caps, PT_CAP_mtc) &&
+ !test_bit((data & RTIT_CTL_MTC_RANGE) >>
+ RTIT_CTL_MTC_RANGE_OFFSET, &value))
+ return 1;
+ value = __pt_cap_get(vmx->pt_desc.caps, PT_CAP_cycle_thresholds);
+ if (__pt_cap_get(vmx->pt_desc.caps, PT_CAP_psb_cyc) &&
+ !test_bit((data & RTIT_CTL_CYC_THRESH) >>
+ RTIT_CTL_CYC_THRESH_OFFSET, &value))
+ return 1;
+ value = __pt_cap_get(vmx->pt_desc.caps, PT_CAP_psb_periods);
+ if (__pt_cap_get(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.range_cnt < 1)) || (value > 2))
+ return 1;
+ value = (data & RTIT_CTL_ADDR1) >> RTIT_CTL_ADDR1_OFFSET;
+ if ((value && (vmx->pt_desc.range_cnt < 2)) || (value > 2))
+ return 1;
+ value = (data & RTIT_CTL_ADDR2) >> RTIT_CTL_ADDR2_OFFSET;
+ if ((value && (vmx->pt_desc.range_cnt < 3)) || (value > 2))
+ return 1;
+ value = (data & RTIT_CTL_ADDR3) >> RTIT_CTL_ADDR3_OFFSET;
+ if ((value && (vmx->pt_desc.range_cnt < 4)) || (value > 2))
+ return 1;
+
+ return 0;
+}
+
+
static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
{
unsigned long rip;
@@ -3651,6 +3722,48 @@ 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) ||
+ !__pt_cap_get(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) ||
+ (!__pt_cap_get(vmx->pt_desc.caps, PT_CAP_topa_output) &&
+ !__pt_cap_get(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) ||
+ (!__pt_cap_get(vmx->pt_desc.caps, PT_CAP_topa_output) &&
+ !__pt_cap_get(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:
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (msr_info->index - MSR_IA32_RTIT_ADDR0_A >=
+ 2 * __pt_cap_get(vmx->pt_desc.caps,
+ PT_CAP_num_address_ranges)))
+ return 1;
+ msr_info->data =
+ vmx->pt_desc.guest.addrs[msr_info->index -
+ MSR_IA32_RTIT_ADDR0_A];
+ break;
case MSR_TSC_AUX:
if (!msr_info->host_initiated &&
!guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))
@@ -3836,6 +3949,56 @@ 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) ||
+ !__pt_cap_get(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) ||
+ (!__pt_cap_get(vmx->pt_desc.caps, PT_CAP_topa_output) &&
+ !__pt_cap_get(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) ||
+ (!__pt_cap_get(vmx->pt_desc.caps, PT_CAP_topa_output) &&
+ !__pt_cap_get(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:
+ if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) ||
+ (msr_info->index - MSR_IA32_RTIT_ADDR0_A >=
+ 2 * __pt_cap_get(vmx->pt_desc.caps,
+ PT_CAP_num_address_ranges)))
+ return 1;
+ vmx->pt_desc.guest.addrs[msr_info->index -
+ MSR_IA32_RTIT_ADDR0_A] = data;
+ break;
case MSR_TSC_AUX:
if (!msr_info->host_initiated &&
!guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 51ecd38..cea0ee2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -69,6 +69,7 @@
#include <asm/irq_remapping.h>
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
+#include <asm/intel_pt.h>

#define CREATE_TRACE_POINTS
#include "trace.h"
@@ -1023,7 +1024,13 @@ bool kvm_rdpmc(struct kvm_vcpu *vcpu)
#endif
MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
- MSR_IA32_SPEC_CTRL, MSR_IA32_ARCH_CAPABILITIES
+ MSR_IA32_SPEC_CTRL, MSR_IA32_ARCH_CAPABILITIES,
+ MSR_IA32_RTIT_CTL, MSR_IA32_RTIT_STATUS, MSR_IA32_RTIT_CR3_MATCH,
+ MSR_IA32_RTIT_OUTPUT_BASE, MSR_IA32_RTIT_OUTPUT_MASK,
+ MSR_IA32_RTIT_ADDR0_A, MSR_IA32_RTIT_ADDR0_B,
+ MSR_IA32_RTIT_ADDR1_A, MSR_IA32_RTIT_ADDR1_B,
+ MSR_IA32_RTIT_ADDR2_A, MSR_IA32_RTIT_ADDR2_B,
+ MSR_IA32_RTIT_ADDR3_A, MSR_IA32_RTIT_ADDR3_B,
};

static unsigned num_msrs_to_save;
@@ -4592,6 +4599,30 @@ static void kvm_init_msr_list(void)
if (!kvm_x86_ops->rdtscp_supported())
continue;
break;
+ case MSR_IA32_RTIT_CTL:
+ case MSR_IA32_RTIT_STATUS:
+ if (!kvm_x86_ops->pt_supported())
+ continue;
+ break;
+ case MSR_IA32_RTIT_CR3_MATCH:
+ if (!kvm_x86_ops->pt_supported() ||
+ !pt_cap_get(PT_CAP_cr3_filtering))
+ continue;
+ break;
+ case MSR_IA32_RTIT_OUTPUT_BASE:
+ case MSR_IA32_RTIT_OUTPUT_MASK:
+ if (!kvm_x86_ops->pt_supported() ||
+ (!pt_cap_get(PT_CAP_topa_output) &&
+ !pt_cap_get(PT_CAP_single_range_output)))
+ continue;
+ break;
+ case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B: {
+ if (!kvm_x86_ops->pt_supported() ||
+ msrs_to_save[i] - MSR_IA32_RTIT_ADDR0_A >=
+ 2 * pt_cap_get(PT_CAP_num_address_ranges))
+ continue;
+ break;
+ }
default:
break;
}
--
1.8.3.1