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Commit 8fe8ab46 authored by Will Auld's avatar Will Auld Committed by Marcelo Tosatti
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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: default avatarWill Auld <will.auld@intel.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 5419369e

arch/x86/include/asm/kvm_host.h

+9 −3
Original line number Diff line number Diff line
@@ -620,6 +620,12 @@ 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 */
@@ -642,7 +648,7 @@ struct kvm_x86_ops { 


	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 @@ 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;
@@ -820,7 +826,7 @@ 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);

arch/x86/kvm/svm.c

+10 −4
Original line number Diff line number Diff line
@@ -3127,13 +3127,15 @@ 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;
@@ -3188,20 +3190,24 @@ 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 {

arch/x86/kvm/vmx.c

+12 −6
Original line number Diff line number Diff line
@@ -2220,15 +2220,17 @@ 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:
@@ -2254,7 +2256,7 @@ 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) {
@@ -2262,7 +2264,7 @@ 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)
@@ -2285,7 +2287,7 @@ 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;
@@ -4648,11 +4650,15 @@ 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;

arch/x86/kvm/x86.c

+24 −7
Original line number Diff line number Diff line
@@ -890,9 +890,9 @@ 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);

}



/*
@@ -900,7 +900,12 @@ 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);

}



#ifdef CONFIG_X86_64
@@ -1130,13 +1135,14 @@ void kvm_track_tsc_matching(struct kvm_vcpu *vcpu) 
#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 @@ 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:
@@ -4531,7 +4539,12 @@ 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 = 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_setup(struct kvm_vcpu *vcpu) 
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;

arch/x86/kvm/x86.h

+1 −1
Original line number Diff line number Diff line
@@ -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,