Commit e3267cbb authored by Glauber Costa's avatar Glauber Costa Committed by Avi Kivity
Browse files

KVM: x86: include pvclock MSRs in msrs_to_save 



For a while now, we are issuing a rdmsr instruction to find out which
msrs in our save list are really supported by the underlying machine.
However, it fails to account for kvm-specific msrs, such as the pvclock
ones.

This patch moves then to the beginning of the list, and skip testing them.

Cc: stable@kernel.org
Signed-off-by: default avatarGlauber Costa <glommer@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 91586a3b

arch/x86/kvm/x86.c

+8 −4
Original line number Diff line number Diff line
@@ -503,16 +503,19 @@ static inline u32 bit(int bitno) 
 * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.

 *

 * This list is modified at module load time to reflect the

 * capabilities of the host cpu.

 * capabilities of the host cpu. This capabilities test skips MSRs that are

 * kvm-specific. Those are put in the beginning of the list.

 */



#define KVM_SAVE_MSRS_BEGIN	2

static u32 msrs_to_save[] = {

	MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,

	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,

	MSR_K6_STAR,

#ifdef CONFIG_X86_64

	MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,

#endif

	MSR_IA32_TSC, MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,

	MSR_IA32_PERF_STATUS, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA

	MSR_IA32_TSC, MSR_IA32_PERF_STATUS, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA

};



static unsigned num_msrs_to_save;
@@ -2446,7 +2449,8 @@ static void kvm_init_msr_list(void) 
	u32 dummy[2];

	unsigned i, j;



	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {

	/* skip the first msrs in the list. KVM-specific */

	for (i = j = KVM_SAVE_MSRS_BEGIN; i < ARRAY_SIZE(msrs_to_save); i++) {

		if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)

			continue;

		if (j < i)

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