[PATCH V3 1/2] Resend - Add code to track call origin for msr assignment.

Will Auld
2012-11-26T18:40:54Z

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 other tasks.

Signed-off-by: Will Auld <will.auld@intel.com>
---
arch/x86/include/asm/kvm_host.h | 12 +++++++++---
arch/x86/kvm/svm.c | 21 +++++++++++++++------
arch/x86/kvm/vmx.c | 24 +++++++++++++++++-------
arch/x86/kvm/x86.c | 23 +++++++++++++++++------
arch/x86/kvm/x86.h | 2 +-
5 files changed, 59 insertions(+), 23 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 09155d6..da34027 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -598,6 +598,12 @@ struct kvm_vcpu_stat {

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 */
@@ -621,7 +627,7 @@ struct kvm_x86_ops {
void (*set_guest_debug)(struct kvm_vcpu *vcpu,
struct kvm_guest_debug *dbg);
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);
@@ -772,7 +778,7 @@ static inline int emulate_instruction(struct kvm_vcpu *vcpu,

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;

@@ -799,7 +805,7 @@ void kvm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l);
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 baead95..5ac11f0 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1211,6 +1211,7 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
struct page *msrpm_pages;
struct page *hsave_page;
struct page *nested_msrpm_pages;
+ struct msr_data msr;
int err;

svm = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
@@ -1255,7 +1256,10 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
svm->vmcb_pa = page_to_pfn(page) << PAGE_SHIFT;
svm->asid_generation = 0;
init_vmcb(svm);
- kvm_write_tsc(&svm->vcpu, 0);
+ msr.data = 0x0;
+ msr.index = MSR_IA32_TSC;
+ msr.host_initiated = true;
+ kvm_write_tsc(&svm->vcpu, &msr);

err = fx_init(&svm->vcpu);
if (err)
@@ -3147,13 +3151,15 @@ static int svm_set_vm_cr(struct kvm_vcpu *vcpu, u64 data)
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;
@@ -3208,20 +3214,23 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)
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 c00f03d..819970f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2197,15 +2197,17 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
* 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:
@@ -2231,7 +2233,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
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) {
@@ -2239,7 +2241,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
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)
@@ -2262,7 +2264,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
}
break;
}
- ret = kvm_set_msr_common(vcpu, msr_index, data);
+ ret = kvm_set_msr_common(vcpu, msr_info);
}

return ret;
@@ -3835,6 +3837,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
unsigned long a;
#endif
int i;
+ struct msr_data msr;

/* I/O */
vmcs_write64(IO_BITMAP_A, __pa(vmx_io_bitmap_a));
@@ -3918,7 +3921,10 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
vmcs_writel(CR0_GUEST_HOST_MASK, ~0UL);
set_cr4_guest_host_mask(vmx);

- kvm_write_tsc(&vmx->vcpu, 0);
+ msr.data = 0x0;
+ msr.index = MSR_IA32_TSC;
+ msr.host_initiated = true;
+ kvm_write_tsc(&vmx->vcpu, &msr);

return 0;
}
@@ -4649,11 +4655,15 @@ static int handle_rdmsr(struct kvm_vcpu *vcpu)

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 42bce48..a3aac1c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -883,9 +883,9 @@ EXPORT_SYMBOL_GPL(kvm_enable_efer_bits);
* 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);
}

/*
@@ -893,7 +893,11 @@ int kvm_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
*/
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);
}

static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
@@ -1043,12 +1047,13 @@ static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
return tsc;
}

-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;
+ u64 data = msr->data;

raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
@@ -1561,9 +1566,11 @@ static void record_steal_time(struct kvm_vcpu *vcpu)
&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:
@@ -4286,7 +4293,11 @@ static int emulator_get_msr(struct x86_emulate_ctxt *ctxt,
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 = true;
+ return kvm_set_msr(emul_to_vcpu(ctxt), &msr);
}

static int emulator_read_pmc(struct x86_emulate_ctxt *ctxt,
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 3d1134d..1dcb8e3 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -112,7 +112,7 @@ void kvm_before_handle_nmi(struct kvm_vcpu *vcpu);
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,
--
1.8.0.rc0