KVM: x86: Add code to track call origin for msr assignment
In order to track who initiated the call (host or guest) to modify an msr
value I have changed function call parameters along the call path. The
specific change is to add a struct pointer parameter that points to (index,
data, caller) information rather than having this information passed as
individual parameters.
The initial use for this capability is for updating the IA32_TSC_ADJUST msr
while setting the tsc value. It is anticipated that this capability is
useful for other tasks.
Signed-off-by: Will Auld <will.auld@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9fb6d8d..56c5dca 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -620,6 +620,12 @@
struct x86_instruction_info;
+struct msr_data {
+ bool host_initiated;
+ u32 index;
+ u64 data;
+};
+
struct kvm_x86_ops {
int (*cpu_has_kvm_support)(void); /* __init */
int (*disabled_by_bios)(void); /* __init */
@@ -642,7 +648,7 @@
void (*update_db_bp_intercept)(struct kvm_vcpu *vcpu);
int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata);
- int (*set_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
+ int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr);
u64 (*get_segment_base)(struct kvm_vcpu *vcpu, int seg);
void (*get_segment)(struct kvm_vcpu *vcpu,
struct kvm_segment *var, int seg);
@@ -793,7 +799,7 @@
void kvm_enable_efer_bits(u64);
int kvm_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *data);
-int kvm_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
+int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr);
struct x86_emulate_ctxt;
@@ -820,7 +826,7 @@
int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr);
int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata);
-int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data);
+int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr);
unsigned long kvm_get_rflags(struct kvm_vcpu *vcpu);
void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 161a5fa..fc22e58 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3127,13 +3127,15 @@
return 0;
}
-static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)
+static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
{
struct vcpu_svm *svm = to_svm(vcpu);
+ u32 ecx = msr->index;
+ u64 data = msr->data;
switch (ecx) {
case MSR_IA32_TSC:
- kvm_write_tsc(vcpu, data);
+ kvm_write_tsc(vcpu, msr);
break;
case MSR_STAR:
svm->vmcb->save.star = data;
@@ -3188,20 +3190,24 @@
vcpu_unimpl(vcpu, "unimplemented wrmsr: 0x%x data 0x%llx\n", ecx, data);
break;
default:
- return kvm_set_msr_common(vcpu, ecx, data);
+ return kvm_set_msr_common(vcpu, msr);
}
return 0;
}
static int wrmsr_interception(struct vcpu_svm *svm)
{
+ struct msr_data msr;
u32 ecx = svm->vcpu.arch.regs[VCPU_REGS_RCX];
u64 data = (svm->vcpu.arch.regs[VCPU_REGS_RAX] & -1u)
| ((u64)(svm->vcpu.arch.regs[VCPU_REGS_RDX] & -1u) << 32);
+ msr.data = data;
+ msr.index = ecx;
+ msr.host_initiated = false;
svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;
- if (svm_set_msr(&svm->vcpu, ecx, data)) {
+ if (svm_set_msr(&svm->vcpu, &msr)) {
trace_kvm_msr_write_ex(ecx, data);
kvm_inject_gp(&svm->vcpu, 0);
} else {
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3606154..45ffa32 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2220,15 +2220,17 @@
* Returns 0 on success, non-0 otherwise.
* Assumes vcpu_load() was already called.
*/
-static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
+static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct shared_msr_entry *msr;
int ret = 0;
+ u32 msr_index = msr_info->index;
+ u64 data = msr_info->data;
switch (msr_index) {
case MSR_EFER:
- ret = kvm_set_msr_common(vcpu, msr_index, data);
+ ret = kvm_set_msr_common(vcpu, msr_info);
break;
#ifdef CONFIG_X86_64
case MSR_FS_BASE:
@@ -2254,7 +2256,7 @@
vmcs_writel(GUEST_SYSENTER_ESP, data);
break;
case MSR_IA32_TSC:
- kvm_write_tsc(vcpu, data);
+ kvm_write_tsc(vcpu, msr_info);
break;
case MSR_IA32_CR_PAT:
if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
@@ -2262,7 +2264,7 @@
vcpu->arch.pat = data;
break;
}
- ret = kvm_set_msr_common(vcpu, msr_index, data);
+ ret = kvm_set_msr_common(vcpu, msr_info);
break;
case MSR_TSC_AUX:
if (!vmx->rdtscp_enabled)
@@ -2285,7 +2287,7 @@
}
break;
}
- ret = kvm_set_msr_common(vcpu, msr_index, data);
+ ret = kvm_set_msr_common(vcpu, msr_info);
}
return ret;
@@ -4648,11 +4650,15 @@
static int handle_wrmsr(struct kvm_vcpu *vcpu)
{
+ struct msr_data msr;
u32 ecx = vcpu->arch.regs[VCPU_REGS_RCX];
u64 data = (vcpu->arch.regs[VCPU_REGS_RAX] & -1u)
| ((u64)(vcpu->arch.regs[VCPU_REGS_RDX] & -1u) << 32);
- if (vmx_set_msr(vcpu, ecx, data) != 0) {
+ msr.data = data;
+ msr.index = ecx;
+ msr.host_initiated = false;
+ if (vmx_set_msr(vcpu, &msr) != 0) {
trace_kvm_msr_write_ex(ecx, data);
kvm_inject_gp(vcpu, 0);
return 1;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fd76621..95f6613 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -890,9 +890,9 @@
* Returns 0 on success, non-0 otherwise.
* Assumes vcpu_load() was already called.
*/
-int kvm_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
+int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
{
- return kvm_x86_ops->set_msr(vcpu, msr_index, data);
+ return kvm_x86_ops->set_msr(vcpu, msr);
}
/*
@@ -900,7 +900,12 @@
*/
static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
{
- return kvm_set_msr(vcpu, index, *data);
+ struct msr_data msr;
+
+ msr.data = *data;
+ msr.index = index;
+ msr.host_initiated = true;
+ return kvm_set_msr(vcpu, &msr);
}
#ifdef CONFIG_X86_64
@@ -1130,13 +1135,14 @@
#endif
}
-void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data)
+void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr)
{
struct kvm *kvm = vcpu->kvm;
u64 offset, ns, elapsed;
unsigned long flags;
s64 usdiff;
bool matched;
+ u64 data = msr->data;
raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
@@ -1857,9 +1863,11 @@
&vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
}
-int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
bool pr = false;
+ u32 msr = msr_info->index;
+ u64 data = msr_info->data;
switch (msr) {
case MSR_EFER:
@@ -4531,7 +4539,12 @@
static int emulator_set_msr(struct x86_emulate_ctxt *ctxt,
u32 msr_index, u64 data)
{
- return kvm_set_msr(emul_to_vcpu(ctxt), msr_index, data);
+ struct msr_data msr;
+
+ msr.data = data;
+ msr.index = msr_index;
+ msr.host_initiated = false;
+ return kvm_set_msr(emul_to_vcpu(ctxt), &msr);
}
static int emulator_read_pmc(struct x86_emulate_ctxt *ctxt,
@@ -6375,11 +6388,15 @@
int kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
int r;
+ struct msr_data msr;
r = vcpu_load(vcpu);
if (r)
return r;
- kvm_write_tsc(vcpu, 0);
+ msr.data = 0x0;
+ msr.index = MSR_IA32_TSC;
+ msr.host_initiated = true;
+ kvm_write_tsc(vcpu, &msr);
vcpu_put(vcpu);
return r;
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 2b5219c..e224f7a 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -112,7 +112,7 @@
void kvm_after_handle_nmi(struct kvm_vcpu *vcpu);
int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);
-void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data);
+void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr);
int kvm_read_guest_virt(struct x86_emulate_ctxt *ctxt,
gva_t addr, void *val, unsigned int bytes,
