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Subject[PATCH 07/26] KVM: VMX: Add helpers to query Intel PT mode
Date
Add helpers to query which of the (two) supported PT modes is active.
The primary motivation is to help document that there is a third PT mode
(host-only) that's currently not supported by KVM. As is, it's not
obvious that PT_MODE_SYSTEM != !PT_MODE_HOST_GUEST and vice versa, e.g.
that "pt_mode == PT_MODE_SYSTEM" and "pt_mode != PT_MODE_HOST_GUEST" are
two distinct checks.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/vmx/capabilities.h | 18 ++++++++++++++++++
arch/x86/kvm/vmx/nested.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 26 +++++++++++++-------------
arch/x86/kvm/vmx/vmx.h | 4 ++--
4 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 283bdb7071af..1a6a99382e94 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -353,4 +353,22 @@ static inline bool cpu_has_vmx_intel_pt(void)
(vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_RTIT_CTL);
}

+/*
+ * Processor Trace can operate in one of three modes:
+ * a. system-wide: trace both host/guest and output to host buffer
+ * b. host-only: only trace host and output to host buffer
+ * c. host-guest: trace host and guest simultaneously and output to their
+ * respective buffer
+ *
+ * KVM currently only supports (a) and (c).
+ */
+static inline bool vmx_pt_mode_is_system(void)
+{
+ return pt_mode == PT_MODE_SYSTEM;
+}
+static inline bool vmx_pt_mode_is_host_guest(void)
+{
+ return pt_mode == PT_MODE_HOST_GUEST;
+}
+
#endif /* __KVM_X86_VMX_CAPS_H */
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 7608924ee8c1..e3c29cf0ffaf 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4543,7 +4543,7 @@ static int enter_vmx_operation(struct kvm_vcpu *vcpu)
vmx->nested.vmcs02_initialized = false;
vmx->nested.vmxon = true;

- if (pt_mode == PT_MODE_HOST_GUEST) {
+ if (vmx_pt_mode_is_host_guest()) {
vmx->pt_desc.guest.ctl = 0;
pt_update_intercept_for_msr(vmx);
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index dbeef64f7409..de62ce6fd3b9 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1059,7 +1059,7 @@ static unsigned long segment_base(u16 selector)

static inline bool pt_can_write_msr(struct vcpu_vmx *vmx)
{
- return (pt_mode == PT_MODE_HOST_GUEST) &&
+ return vmx_pt_mode_is_host_guest() &&
!(vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN);
}

@@ -1093,7 +1093,7 @@ static inline void pt_save_msr(struct pt_ctx *ctx, u32 addr_range)

static void pt_guest_enter(struct vcpu_vmx *vmx)
{
- if (pt_mode == PT_MODE_SYSTEM)
+ if (vmx_pt_mode_is_system())
return;

/*
@@ -1110,7 +1110,7 @@ static void pt_guest_enter(struct vcpu_vmx *vmx)

static void pt_guest_exit(struct vcpu_vmx *vmx)
{
- if (pt_mode == PT_MODE_SYSTEM)
+ if (vmx_pt_mode_is_system())
return;

if (vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) {
@@ -1856,24 +1856,24 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return vmx_get_vmx_msr(&vmx->nested.msrs, msr_info->index,
&msr_info->data);
case MSR_IA32_RTIT_CTL:
- if (pt_mode != PT_MODE_HOST_GUEST)
+ if (!vmx_pt_mode_is_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)
+ if (!vmx_pt_mode_is_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) ||
+ if (!vmx_pt_mode_is_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) ||
+ if (!vmx_pt_mode_is_host_guest() ||
(!intel_pt_validate_cap(vmx->pt_desc.caps,
PT_CAP_topa_output) &&
!intel_pt_validate_cap(vmx->pt_desc.caps,
@@ -1882,7 +1882,7 @@ 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 ((pt_mode != PT_MODE_HOST_GUEST) ||
+ if (!vmx_pt_mode_is_host_guest() ||
(!intel_pt_validate_cap(vmx->pt_desc.caps,
PT_CAP_topa_output) &&
!intel_pt_validate_cap(vmx->pt_desc.caps,
@@ -1892,7 +1892,7 @@ 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 ((pt_mode != PT_MODE_HOST_GUEST) ||
+ if (!vmx_pt_mode_is_host_guest() ||
(index >= 2 * intel_pt_validate_cap(vmx->pt_desc.caps,
PT_CAP_num_address_ranges)))
return 1;
@@ -2098,7 +2098,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return 1;
return vmx_set_vmx_msr(vcpu, msr_index, data);
case MSR_IA32_RTIT_CTL:
- if ((pt_mode != PT_MODE_HOST_GUEST) ||
+ if (!vmx_pt_mode_is_host_guest() ||
vmx_rtit_ctl_check(vcpu, data) ||
vmx->nested.vmxon)
return 1;
@@ -4001,7 +4001,7 @@ static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx)

u32 exec_control = vmcs_config.cpu_based_2nd_exec_ctrl;

- if (pt_mode == PT_MODE_SYSTEM)
+ if (vmx_pt_mode_is_system())
exec_control &= ~(SECONDARY_EXEC_PT_USE_GPA | SECONDARY_EXEC_PT_CONCEAL_VMX);
if (!cpu_need_virtualize_apic_accesses(vcpu))
exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;
@@ -4242,7 +4242,7 @@ static void init_vmcs(struct vcpu_vmx *vmx)
if (cpu_has_vmx_encls_vmexit())
vmcs_write64(ENCLS_EXITING_BITMAP, -1ull);

- if (pt_mode == PT_MODE_HOST_GUEST) {
+ if (vmx_pt_mode_is_host_guest()) {
memset(&vmx->pt_desc, 0, sizeof(vmx->pt_desc));
/* Bit[6~0] are forced to 1, writes are ignored. */
vmx->pt_desc.guest.output_mask = 0x7F;
@@ -6309,7 +6309,7 @@ static bool vmx_has_emulated_msr(u32 index)

static bool vmx_pt_supported(void)
{
- return pt_mode == PT_MODE_HOST_GUEST;
+ return vmx_pt_mode_is_host_guest();
}

static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index a4f7f737c5d4..70eafa88876a 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -449,7 +449,7 @@ static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
static inline u32 vmx_vmentry_ctrl(void)
{
u32 vmentry_ctrl = vmcs_config.vmentry_ctrl;
- if (pt_mode == PT_MODE_SYSTEM)
+ if (vmx_pt_mode_is_system())
vmentry_ctrl &= ~(VM_ENTRY_PT_CONCEAL_PIP |
VM_ENTRY_LOAD_IA32_RTIT_CTL);
/* Loading of EFER and PERF_GLOBAL_CTRL are toggled dynamically */
@@ -460,7 +460,7 @@ static inline u32 vmx_vmentry_ctrl(void)
static inline u32 vmx_vmexit_ctrl(void)
{
u32 vmexit_ctrl = vmcs_config.vmexit_ctrl;
- if (pt_mode == PT_MODE_SYSTEM)
+ if (vmx_pt_mode_is_system())
vmexit_ctrl &= ~(VM_EXIT_PT_CONCEAL_PIP |
VM_EXIT_CLEAR_IA32_RTIT_CTL);
/* Loading of EFER and PERF_GLOBAL_CTRL are toggled dynamically */
--
2.24.1
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