The new implementation of VMX DEBUGCTLMSR is moved to here.
Using msr intercept bitmap and arrays(save/restore LBR MSRs)
in kvm_vcpu_arch struct to support LBR virtualization, and
a parameter of kvm_intel module is added to permanently disable LBRV.
Userspace can get/set contents of LBR MSRs, so the migration is supported.
Signed-off-by: Jian Zhou <jianjay.zhou@xxxxxxxxxx>
Signed-off-by: Stephen He <herongguang.he@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 335 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 335 insertions(+)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 6a8bc64..2d4e90b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -90,6 +90,9 @@ module_param(fasteoi, bool, S_IRUGO);
static bool __read_mostly enable_apicv = 1;
module_param(enable_apicv, bool, S_IRUGO);
+static bool __read_mostly lbrv = 1;
+module_param(lbrv, bool, S_IRUGO);
+
static bool __read_mostly enable_shadow_vmcs = 1;
module_param_named(enable_shadow_vmcs, enable_shadow_vmcs, bool, S_IRUGO);
/*
@@ -2617,6 +2620,256 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
return 0;
}
+struct lbr_info {
+ u32 base;
+ u8 count;
+} pentium4_lbr[] = {
+ { MSR_PENTIUM4_LER_FROM_LIP, 1 },
+ { MSR_PENTIUM4_LER_TO_LIP, 1 },
+ { MSR_PENTIUM4_LBR_TOS, 1 },
+ { MSR_LBR_PENTIUM4_FROM, SIZE_PENTIUM4_LBR_STACK },
+ { MSR_LBR_PENTIUM4_TO, SIZE_PENTIUM4_LBR_STACK },
+ { 0, 0 }
+}, core2_lbr[] = {
+ { MSR_IA32_LASTINTFROMIP, 1 },
+ { MSR_IA32_LASTINTTOIP, 1 },
+ { MSR_LBR_TOS, 1 },
+ { MSR_LBR_CORE2_FROM, SIZE_CORE2_LBR_STACK },
+ { MSR_LBR_CORE2_TO, SIZE_CORE2_LBR_STACK },
+ { 0, 0 }
+}, atom_lbr[] = {
+ { MSR_IA32_LASTINTFROMIP, 1 },
+ { MSR_IA32_LASTINTTOIP, 1 },
+ { MSR_LBR_TOS, 1 },
+ { MSR_LBR_ATOM_FROM, SIZE_ATOM_LBR_STACK },
+ { MSR_LBR_ATOM_TO, SIZE_ATOM_LBR_STACK },
+ { 0, 0 }
+}, nehalem_lbr[] = {
+ { MSR_LBR_SELECT, 1 },
+ { MSR_IA32_LASTINTFROMIP, 1 },
+ { MSR_IA32_LASTINTTOIP, 1 },
+ { MSR_LBR_TOS, 1 },
+ { MSR_LBR_NHM_FROM, SIZE_NHM_LBR_STACK },
+ { MSR_LBR_NHM_TO, SIZE_NHM_LBR_STACK },
+ { 0, 0 }
+}, skylake_lbr[] = {
+ { MSR_LBR_SELECT, 1 },
+ { MSR_IA32_LASTINTFROMIP, 1 },
+ { MSR_IA32_LASTINTTOIP, 1 },
+ { MSR_LBR_TOS, 1 },
+ { MSR_LBR_SKYLAKE_FROM, SIZE_SKYLAKE_LBR_STACK },
+ { MSR_LBR_SKYLAKE_TO, SIZE_SKYLAKE_LBR_STACK },
+ { 0, 0}
+};
+
+static const struct lbr_info *last_branch_msr_get(u8 family, u8 model)
+{
+ if (family == 6)
+ {
+ switch (model)
+ {
+ case 15: /* 65nm Core2 "Merom" */
+ case 22: /* 65nm Core2 "Merom-L" */
+ case 23: /* 45nm Core2 "Penryn" */
+ case 29: /* 45nm Core2 "Dunnington (MP) */
+ return core2_lbr;
+ break;
+ case 28: /* 45nm Atom "Pineview" */
+ case 38: /* 45nm Atom "Lincroft" */
+ case 39: /* 32nm Atom "Penwell" */
+ case 53: /* 32nm Atom "Cloverview" */
+ case 54: /* 32nm Atom "Cedarview" */
+ case 55: /* 22nm Atom "Silvermont" */
+ case 76: /* 14nm Atom "Airmont" */
+ case 77: /* 22nm Atom "Silvermont Avoton/Rangely" */
+ return atom_lbr;
+ break;
+ case 30: /* 45nm Nehalem */
+ case 26: /* 45nm Nehalem-EP */
+ case 46: /* 45nm Nehalem-EX */
+ case 37: /* 32nm Westmere */
+ case 44: /* 32nm Westmere-EP */
+ case 47: /* 32nm Westmere-EX */
+ case 42: /* 32nm SandyBridge */
+ case 45: /* 32nm SandyBridge-E/EN/EP */
+ case 58: /* 22nm IvyBridge */
+ case 62: /* 22nm IvyBridge-EP/EX */
+ case 60: /* 22nm Haswell Core */
+ case 63: /* 22nm Haswell Server */
+ case 69: /* 22nm Haswell ULT */
+ case 70: /* 22nm Haswell + GT3e */
+ case 61: /* 14nm Broadwell Core-M */
+ case 86: /* 14nm Broadwell Xeon D */
+ case 71: /* 14nm Broadwell + GT3e */
+ case 79: /* 14nm Broadwell Server */
+ return nehalem_lbr;
+ break;
+ case 78: /* 14nm Skylake Mobile */
+ case 94: /* 14nm Skylake Desktop */
+ return skylake_lbr;
+ break;
+ }
+ }
+ if (family == 15) {
+ switch (model)
+ {
+ /* Pentium4/Xeon(based on NetBurst)*/
+ case 3:
+ case 4:
+ case 6:
+ return pentium4_lbr;
+ break;
+ }
+ }
+
+ return NULL;
+}
+
+static void vmx_disable_intercept_guest_msr(struct kvm_vcpu *vcpu, u32 msr);
+
+static int vmx_enable_lbrv(struct kvm_vcpu *vcpu)
+{
+ int i;
+ struct lbr_msr *m = &(vcpu->arch.lbr_msr);
+ const struct lbr_info *host_lbr;
+ const struct lbr_info *guest_lbr;
+ struct kvm_cpuid_entry2 *best;
+ u32 eax;
+ u8 family;
+ u8 model;
+
+ if (vcpu->arch.lbr_used) {
+ vcpu->arch.lbr_status = 1;
+ return 0;
+ }
+
+ best = kvm_find_cpuid_entry(vcpu, 1, 0);
+ eax = best->eax;
+ family = (eax >> 8) & 0xf;
+ model = (eax >> 4) & 0xf;
+
+ if (family == 15)
+ family += (eax >> 20) & 0xff;
+ if (family >= 6)
+ model += ((eax >> 16) & 0xf) << 4;
+
+ host_lbr = last_branch_msr_get(boot_cpu_data.x86,
+ boot_cpu_data.x86_model);
+ guest_lbr = last_branch_msr_get(family, model);
+
+ if ((host_lbr != guest_lbr) || !guest_lbr)
+ return 1;
+
+ for (; guest_lbr->count; guest_lbr++)
+ for (i = 0; (i < guest_lbr->count); i++) {
+ m->host[m->nr].index = guest_lbr->base + i;
+ m->host[m->nr].data = 0;
+ m->guest[m->nr].index = guest_lbr->base + i;
+ m->guest[m->nr].data = 0;
+ m->nr++;
+
+ vmx_disable_intercept_guest_msr(vcpu,
+ guest_lbr->base + i);
+ }
+
+ vcpu->arch.lbr_status = 1;
+ vcpu->arch.lbr_used = 1;
+
+ return 0;
+}
+
+static int vmx_set_debugctlmsr(struct kvm_vcpu *vcpu, u64 data)
+{
+ if (data & DEBUGCTLMSR_LBR) {
+ if (!lbrv) {
+ vcpu_unimpl(vcpu, "disabled MSR_IA32_DEBUGCTLMSR "
+ "wrmsr: data 0x%llx\n", data);
+ return 1;
+ }
+
+ if (vmx_enable_lbrv(vcpu))
+ return 1;
+ } else
+ vcpu->arch.lbr_status = 0;
+
+ vmcs_write64(GUEST_IA32_DEBUGCTL, data);
+
+ return 0;
+}
+
+static u64 vmx_get_debugctlmsr(void)
+{
+ if (lbrv)
+ return vmcs_read64(GUEST_IA32_DEBUGCTL);
+ else
+ return 0;
+}
+
+static void vmx_set_lbr_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
+{
+ unsigned i;
+ u32 msr = msr_info->index;
+ u64 data = msr_info->data;
+ bool found = false;
+ struct lbr_msr *m = &(vcpu->arch.lbr_msr);
+
+ if (!lbrv) {
+ vcpu_unimpl(vcpu, "disabled LBR wrmsr: "
+ "0x%x data 0x%llx\n", msr, data);
+ return;
+ }
+
+ for (i = 0; i < m->nr; ++i)
+ if (m->guest[i].index == msr) {
+ m->guest[i].data = data;
+ found = true;
+ }
+
+ if (!found && vcpu->arch.lbr_used)
+ vcpu_unimpl(vcpu, "ignored LBR wrmsr: 0x%x data %llx\n",
+ msr, data);
+}
+
+static u64 vmx_get_lbr_msr(struct kvm_vcpu *vcpu, u32 msr)
+{
+ unsigned i;
+ struct lbr_msr *m = &(vcpu->arch.lbr_msr);
+
+ if (!lbrv)
+ return 0;
+
+ for (i = 0; i < m->nr; ++i)
+ if (m->guest[i].index == msr)
+ break;
+
+ if (i < m->nr)
+ return m->guest[i].data;
+ else if (vcpu->arch.lbr_used)
+ vcpu_unimpl(vcpu, "ignored LBR rdmsr: 0x%x\n", msr);
+
+ return 0;
+}
+
+static void switch_lbr_msrs(struct kvm_vcpu *vcpu, int vm_exit)
+{
+ int i;
+ struct lbr_msr *m = &(vcpu->arch.lbr_msr);
+
+ if (!vcpu->arch.lbr_used)
+ return;
+
+ for (i = 0; i < m->nr; ++i) {
+ if (vm_exit) {
+ rdmsrl(m->guest[i].index, m->guest[i].data);
+ wrmsrl(m->host[i].index, m->host[i].data);
+ }
+ else {
+ rdmsrl(m->host[i].index, m->host[i].data);
+ wrmsrl(m->guest[i].index, m->guest[i].data);
+ }
+ }
+}
+
/*
* Reads an msr value (of 'msr_index') into 'pdata'.
* Returns 0 on success, non-0 otherwise.
@@ -2653,6 +2906,27 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_IA32_SYSENTER_ESP:
msr_info->data = vmcs_readl(GUEST_SYSENTER_ESP);
break;
+ case MSR_IA32_DEBUGCTLMSR:
+ msr_info->data = vmx_get_debugctlmsr();
+ break;
+ case MSR_LBR_STATUS:
+ msr_info->data = vcpu->arch.lbr_status;
+ break;
+ case MSR_LBR_SELECT:
+ case MSR_LBR_TOS:
+ case MSR_PENTIUM4_LER_FROM_LIP:
+ case MSR_PENTIUM4_LER_TO_LIP:
+ case MSR_PENTIUM4_LBR_TOS:
+ case MSR_IA32_LASTINTFROMIP:
+ case MSR_IA32_LASTINTTOIP:
+ case MSR_LBR_ATOM_FROM ... MSR_LBR_ATOM_FROM + SIZE_ATOM_LBR_STACK - 1:
+ case MSR_LBR_ATOM_TO ... MSR_LBR_ATOM_TO + SIZE_ATOM_LBR_STACK - 1:
+ case MSR_LBR_SKYLAKE_FROM ...
+ MSR_LBR_SKYLAKE_FROM + SIZE_SKYLAKE_LBR_STACK - 1:
+ case MSR_LBR_SKYLAKE_TO ...
+ MSR_LBR_SKYLAKE_TO + SIZE_SKYLAKE_LBR_STACK - 1:
+ msr_info->data = vmx_get_lbr_msr(vcpu, msr_info->index);
+ break;
case MSR_IA32_BNDCFGS:
if (!vmx_mpx_supported())
return 1;
@@ -2702,6 +2976,7 @@ 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;
+ u64 supported = 0;
switch (msr_index) {
case MSR_EFER:
@@ -2730,6 +3005,47 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_IA32_SYSENTER_ESP:
vmcs_writel(GUEST_SYSENTER_ESP, data);
break;
+ case MSR_IA32_DEBUGCTLMSR:
+ supported = DEBUGCTLMSR_LBR | DEBUGCTLMSR_BTF |
+ DEBUGCTLMSR_FREEZE_LBRS_ON_PMI;
+
+ if (data & ~supported) {
+ /*
+ * Values other than LBR/BTF/FREEZE_LBRS_ON_PMI
+ * are not supported, thus reserved and should
+ * throw a #GP
+ */
+ vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, "
+ "nop\n", __func__, data);
+ return 1;
+ }
+
+ if (vmx_set_debugctlmsr(vcpu, data))
+ return 1;
+
+ break;
+ case MSR_LBR_STATUS:
+ if (data) {
+ if (!vmx_set_debugctlmsr(vcpu, DEBUGCTLMSR_LBR |
+ DEBUGCTLMSR_FREEZE_LBRS_ON_PMI))
+ vcpu->arch.lbr_status = data;
+ }
+ break;
+ case MSR_LBR_SELECT:
+ case MSR_LBR_TOS:
+ case MSR_PENTIUM4_LER_FROM_LIP:
+ case MSR_PENTIUM4_LER_TO_LIP:
+ case MSR_PENTIUM4_LBR_TOS:
+ case MSR_IA32_LASTINTFROMIP:
+ case MSR_IA32_LASTINTTOIP:
+ case MSR_LBR_ATOM_FROM ... MSR_LBR_ATOM_FROM + SIZE_ATOM_LBR_STACK - 1:
+ case MSR_LBR_ATOM_TO ... MSR_LBR_ATOM_TO + SIZE_ATOM_LBR_STACK - 1:
+ case MSR_LBR_SKYLAKE_FROM ...
+ MSR_LBR_SKYLAKE_FROM + SIZE_SKYLAKE_LBR_STACK - 1:
+ case MSR_LBR_SKYLAKE_TO ...
+ MSR_LBR_SKYLAKE_TO + SIZE_SKYLAKE_LBR_STACK - 1:
+ vmx_set_lbr_msr(vcpu, msr_info);
+ break;
case MSR_IA32_BNDCFGS:
if (!vmx_mpx_supported())
return 1;
@@ -4323,6 +4639,21 @@ static void vmx_disable_intercept_msr_write_x2apic(u32 msr)
msr, MSR_TYPE_W);
}
+static void vmx_disable_intercept_guest_msr(struct kvm_vcpu *vcpu, u32 msr)
+{
+ if (irqchip_in_kernel(vcpu->kvm) &&
+ apic_x2apic_mode(vcpu->arch.apic)) {
+ vmx_disable_intercept_msr_read_x2apic(msr);
+ vmx_disable_intercept_msr_write_x2apic(msr);
+ }
+ else {
+ if (is_long_mode(vcpu))
+ vmx_disable_intercept_for_msr(msr, true);
+ else
+ vmx_disable_intercept_for_msr(msr, false);
+ }
+}
+
static int vmx_vm_has_apicv(struct kvm *kvm)
{
return enable_apicv && irqchip_in_kernel(kvm);
@@ -8304,6 +8635,8 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
atomic_switch_perf_msrs(vmx);
debugctlmsr = get_debugctlmsr();
+ switch_lbr_msrs(vcpu, 0);
+
vmx->__launched = vmx->loaded_vmcs->launched;
asm(
/* Store host registers */
@@ -8410,6 +8743,8 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
#endif
);
+ switch_lbr_msrs(vcpu, 1);
+
/* MSR_IA32_DEBUGCTLMSR is zeroed on vmexit. Restore it if needed */
if (debugctlmsr)
update_debugctlmsr(debugctlmsr);
--
1.7.12.4
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