[PATCH 19/45] KVM: VMX: Add PAT support for EPT

Avi Kivity
2008-12-08T11:48:44Z

From: Sheng Yang <sheng@linux.intel.com>

GUEST_PAT support is a new feature introduced by Intel Core i7 architecture.
With this, cpu would save/load guest and host PAT automatically, for EPT memory
type in guest depends on MSR_IA32_CR_PAT.

Also add save/restore for MSR_IA32_CR_PAT.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---
arch/x86/kvm/vmx.c | 29 ++++++++++++++++++++++++++---
arch/x86/kvm/vmx.h | 7 +++++++
arch/x86/kvm/x86.c | 2 +-
3 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2180109..b4c95a5 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -962,6 +962,13 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
pr_unimpl(vcpu, "unimplemented perfctr wrmsr: 0x%x data 0x%llx\n", msr_index, data);

break;
+ case MSR_IA32_CR_PAT:
+ if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
+ vmcs_write64(GUEST_IA32_PAT, data);
+ vcpu->arch.pat = data;
+ break;
+ }
+ /* Otherwise falls through to kvm_set_msr_common */
default:
vmx_load_host_state(vmx);
msr = find_msr_entry(vmx, msr_index);
@@ -1181,12 +1188,13 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
#ifdef CONFIG_X86_64
min |= VM_EXIT_HOST_ADDR_SPACE_SIZE;
#endif
- opt = 0;
+ opt = VM_EXIT_SAVE_IA32_PAT | VM_EXIT_LOAD_IA32_PAT;
if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_EXIT_CTLS,
&_vmexit_control) < 0)
return -EIO;

- min = opt = 0;
+ min = 0;
+ opt = VM_ENTRY_LOAD_IA32_PAT;
if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_ENTRY_CTLS,
&_vmentry_control) < 0)
return -EIO;
@@ -2092,8 +2100,9 @@ static void vmx_disable_intercept_for_msr(struct page *msr_bitmap, u32 msr)
*/
static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
{
- u32 host_sysenter_cs;
+ u32 host_sysenter_cs, msr_low, msr_high;
u32 junk;
+ u64 host_pat;
unsigned long a;
struct descriptor_table dt;
int i;
@@ -2181,6 +2190,20 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
rdmsrl(MSR_IA32_SYSENTER_EIP, a);
vmcs_writel(HOST_IA32_SYSENTER_EIP, a); /* 22.2.3 */

+ if (vmcs_config.vmexit_ctrl & VM_EXIT_LOAD_IA32_PAT) {
+ rdmsr(MSR_IA32_CR_PAT, msr_low, msr_high);
+ host_pat = msr_low | ((u64) msr_high << 32);
+ vmcs_write64(HOST_IA32_PAT, host_pat);
+ }
+ if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
+ rdmsr(MSR_IA32_CR_PAT, msr_low, msr_high);
+ host_pat = msr_low | ((u64) msr_high << 32);
+ /* Write the default value follow host pat */
+ vmcs_write64(GUEST_IA32_PAT, host_pat);
+ /* Keep arch.pat sync with GUEST_IA32_PAT */
+ vmx->vcpu.arch.pat = host_pat;
+ }
+
for (i = 0; i < NR_VMX_MSR; ++i) {
u32 index = vmx_msr_index[i];
u32 data_low, data_high;
diff --git a/arch/x86/kvm/vmx.h b/arch/x86/kvm/vmx.h
index ec5edc3..18598af 100644
--- a/arch/x86/kvm/vmx.h
+++ b/arch/x86/kvm/vmx.h
@@ -63,10 +63,13 @@

#define VM_EXIT_HOST_ADDR_SPACE_SIZE 0x00000200
#define VM_EXIT_ACK_INTR_ON_EXIT 0x00008000
+#define VM_EXIT_SAVE_IA32_PAT 0x00040000
+#define VM_EXIT_LOAD_IA32_PAT 0x00080000

#define VM_ENTRY_IA32E_MODE 0x00000200
#define VM_ENTRY_SMM 0x00000400
#define VM_ENTRY_DEACT_DUAL_MONITOR 0x00000800
+#define VM_ENTRY_LOAD_IA32_PAT 0x00004000

/* VMCS Encodings */
enum vmcs_field {
@@ -112,6 +115,8 @@ enum vmcs_field {
VMCS_LINK_POINTER_HIGH = 0x00002801,
GUEST_IA32_DEBUGCTL = 0x00002802,
GUEST_IA32_DEBUGCTL_HIGH = 0x00002803,
+ GUEST_IA32_PAT = 0x00002804,
+ GUEST_IA32_PAT_HIGH = 0x00002805,
GUEST_PDPTR0 = 0x0000280a,
GUEST_PDPTR0_HIGH = 0x0000280b,
GUEST_PDPTR1 = 0x0000280c,
@@ -120,6 +125,8 @@ enum vmcs_field {
GUEST_PDPTR2_HIGH = 0x0000280f,
GUEST_PDPTR3 = 0x00002810,
GUEST_PDPTR3_HIGH = 0x00002811,
+ HOST_IA32_PAT = 0x00002c00,
+ HOST_IA32_PAT_HIGH = 0x00002c01,
PIN_BASED_VM_EXEC_CONTROL = 0x00004000,
CPU_BASED_VM_EXEC_CONTROL = 0x00004002,
EXCEPTION_BITMAP = 0x00004004,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f5b2334..0edf753 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -452,7 +452,7 @@ static u32 msrs_to_save[] = {
MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
#endif
MSR_IA32_TIME_STAMP_COUNTER, MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
- MSR_IA32_PERF_STATUS,
+ MSR_IA32_PERF_STATUS, MSR_IA32_CR_PAT
};

static unsigned num_msrs_to_save;
--
1.6.0.3