[PATCH v7 07/13] KVM: x86: Add Intel Processor Trace cpuid emulation

Luwei Kang
2018-05-03T12:13:22Z

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

Expose Intel Processor Trace to guest only when PT work in
HOST_GUEST mode.

Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Signed-off-by: Luwei Kang <luwei.kang@intel.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/cpuid.c | 22 ++++++++++++++++++++--
arch/x86/kvm/svm.c | 6 ++++++
arch/x86/kvm/vmx.c | 6 ++++++
4 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c25775f..03875aa 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1025,6 +1025,7 @@ struct kvm_x86_ops {
bool (*mpx_supported)(void);
bool (*xsaves_supported)(void);
bool (*umip_emulated)(void);
+ bool (*pt_supported)(void);

int (*check_nested_events)(struct kvm_vcpu *vcpu, bool external_intr);

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 82055b9..e04bf67 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -336,6 +336,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0;
+ unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0;

/* cpuid 1.edx */
const u32 kvm_cpuid_1_edx_x86_features =
@@ -393,7 +394,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
- F(SHA_NI) | F(AVX512BW) | F(AVX512VL);
+ F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | f_intel_pt;

/* cpuid 0xD.1.eax */
const u32 kvm_cpuid_D_1_eax_x86_features =
@@ -423,7 +424,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,

switch (function) {
case 0:
- entry->eax = min(entry->eax, (u32)0xd);
+ entry->eax = min(entry->eax, (u32)(f_intel_pt ? 0x14 : 0xd));
break;
case 1:
entry->edx &= kvm_cpuid_1_edx_x86_features;
@@ -595,6 +596,23 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
}
break;
}
+ /* Intel PT */
+ case 0x14: {
+ int t, times = entry->eax;
+
+ if (!f_intel_pt)
+ break;
+
+ entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ for (t = 1; t <= times; ++t) {
+ if (*nent >= maxnent)
+ goto out;
+ do_cpuid_1_ent(&entry[t], function, t);
+ entry[t].flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ ++*nent;
+ }
+ break;
+ }
case KVM_CPUID_SIGNATURE: {
static const char signature[12] = "KVMKVMKVM\0\0";
const u32 *sigptr = (const u32 *)signature;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 80ea262..23a1ef9 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -5877,6 +5877,11 @@ static bool svm_umip_emulated(void)
return false;
}

+static bool svm_pt_supported(void)
+{
+ return false;
+}
+
static bool svm_has_wbinvd_exit(void)
{
return true;
@@ -7102,6 +7107,7 @@ static int svm_unregister_enc_region(struct kvm *kvm,
.mpx_supported = svm_mpx_supported,
.xsaves_supported = svm_xsaves_supported,
.umip_emulated = svm_umip_emulated,
+ .pt_supported = svm_pt_supported,

.set_supported_cpuid = svm_set_supported_cpuid,

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8680cd5..27cf417 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9563,6 +9563,11 @@ static bool vmx_umip_emulated(void)
SECONDARY_EXEC_DESC;
}

+static bool vmx_pt_supported(void)
+{
+ return (pt_mode == PT_MODE_HOST_GUEST);
+}
+
static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
{
u32 exit_intr_info;
@@ -12790,6 +12795,7 @@ static int enable_smi_window(struct kvm_vcpu *vcpu)
.mpx_supported = vmx_mpx_supported,
.xsaves_supported = vmx_xsaves_supported,
.umip_emulated = vmx_umip_emulated,
+ .pt_supported = vmx_pt_supported,

.check_nested_events = vmx_check_nested_events,

--
1.8.3.1