VM_(ENTRY|EXIT)_CONTROLS vmcs fields are read/written on each guest
entry but most times it can be avoided since values do not changes.
Keep fields copy in memory to avoid unnecessary reads from vmcs.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index b2fe1c2..29c1c7f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -418,6 +418,8 @@ struct vcpu_vmx {
u64 msr_host_kernel_gs_base;
u64 msr_guest_kernel_gs_base;
#endif
+ u32 vm_entry_controls_shadow;
+ u32 vm_exit_controls_shadow;
/*
* loaded_vmcs points to the VMCS currently used in this vcpu. For a
* non-nested (L1) guest, it always points to vmcs01. For a nested
@@ -1326,6 +1328,62 @@ static void vmcs_set_bits(unsigned long field, u32 mask)
vmcs_writel(field, vmcs_readl(field) | mask);
}
+static inline void vm_entry_controls_init(struct vcpu_vmx *vmx, u32 val)
+{
+ vmcs_write32(VM_ENTRY_CONTROLS, val);
+ vmx->vm_entry_controls_shadow = val;
+}
+
+static inline void vm_entry_controls_set(struct vcpu_vmx *vmx, u32 val)
+{
+ if (vmx->vm_entry_controls_shadow != val)
+ vm_entry_controls_init(vmx, val);
+}
+
+static inline u32 vm_entry_controls_get(struct vcpu_vmx *vmx)
+{
+ return vmx->vm_entry_controls_shadow;
+}
+
+
+static inline void vm_entry_controls_setbit(struct vcpu_vmx *vmx, u32 val)
+{
+ vm_entry_controls_set(vmx, vm_entry_controls_get(vmx) | val);
+}
+
+static inline void vm_entry_controls_clearbit(struct vcpu_vmx *vmx, u32 val)
+{
+ vm_entry_controls_set(vmx, vm_entry_controls_get(vmx) & ~val);
+}
+
+static inline void vm_exit_controls_init(struct vcpu_vmx *vmx, u32 val)
+{
+ vmcs_write32(VM_EXIT_CONTROLS, val);
+ vmx->vm_exit_controls_shadow = val;
+}
+
+static inline void vm_exit_controls_set(struct vcpu_vmx *vmx, u32 val)
+{
+ if (vmx->vm_exit_controls_shadow != val)
+ vm_exit_controls_init(vmx, val);
+}
+
+static inline u32 vm_exit_controls_get(struct vcpu_vmx *vmx)
+{
+ return vmx->vm_exit_controls_shadow;
+}
+
+
+static inline void vm_exit_controls_setbit(struct vcpu_vmx *vmx, u32 val)
+{
+ vm_exit_controls_set(vmx, vm_exit_controls_get(vmx) | val);
+}
+
+static inline void vm_exit_controls_clearbit(struct vcpu_vmx *vmx, u32 val)
+{
+ vm_exit_controls_set(vmx, vm_exit_controls_get(vmx) & ~val);
+}
+
static void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
{
vmx->segment_cache.bitmask = 0;
@@ -1410,11 +1468,11 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu)
vmcs_write32(EXCEPTION_BITMAP, eb);
}
-static void clear_atomic_switch_msr_special(unsigned long entry,
- unsigned long exit)
+static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx,
+ unsigned long entry, unsigned long exit)
{
- vmcs_clear_bits(VM_ENTRY_CONTROLS, entry);
- vmcs_clear_bits(VM_EXIT_CONTROLS, exit);
+ vm_entry_controls_clearbit(vmx, entry);
+ vm_exit_controls_clearbit(vmx, exit);
}
static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
@@ -1425,14 +1483,15 @@ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
switch (msr) {
case MSR_EFER:
if (cpu_has_load_ia32_efer) {
- clear_atomic_switch_msr_special(VM_ENTRY_LOAD_IA32_EFER,
+ clear_atomic_switch_msr_special(vmx,
+ VM_ENTRY_LOAD_IA32_EFER,
VM_EXIT_LOAD_IA32_EFER);
return;
}
break;
case MSR_CORE_PERF_GLOBAL_CTRL:
if (cpu_has_load_perf_global_ctrl) {
- clear_atomic_switch_msr_special(
+ clear_atomic_switch_msr_special(vmx,
VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL,
VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL);
return;
@@ -1453,14 +1512,15 @@ static void clear_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr)
vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, m->nr);
}
-static void add_atomic_switch_msr_special(unsigned long entry,
- unsigned long exit, unsigned long guest_val_vmcs,
- unsigned long host_val_vmcs, u64 guest_val, u64 host_val)
+static void add_atomic_switch_msr_special(struct vcpu_vmx *vmx,
+ unsigned long entry, unsigned long exit,
+ unsigned long guest_val_vmcs, unsigned long host_val_vmcs,
+ u64 guest_val, u64 host_val)
{
vmcs_write64(guest_val_vmcs, guest_val);
vmcs_write64(host_val_vmcs, host_val);
- vmcs_set_bits(VM_ENTRY_CONTROLS, entry);
- vmcs_set_bits(VM_EXIT_CONTROLS, exit);
+ vm_entry_controls_setbit(vmx, entry);
+ vm_exit_controls_setbit(vmx, exit);
}
static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
@@ -1472,7 +1532,8 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
switch (msr) {
case MSR_EFER:
if (cpu_has_load_ia32_efer) {
- add_atomic_switch_msr_special(VM_ENTRY_LOAD_IA32_EFER,
+ add_atomic_switch_msr_special(vmx,
+ VM_ENTRY_LOAD_IA32_EFER,
VM_EXIT_LOAD_IA32_EFER,
GUEST_IA32_EFER,
HOST_IA32_EFER,
@@ -1482,7 +1543,7 @@ static void add_atomic_switch_msr(struct vcpu_vmx *vmx, unsigned msr,
break;
case MSR_CORE_PERF_GLOBAL_CTRL:
if (cpu_has_load_perf_global_ctrl) {
- add_atomic_switch_msr_special(
+ add_atomic_switch_msr_special(vmx,
VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL,
VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL,
GUEST_IA32_PERF_GLOBAL_CTRL,
@@ -3182,14 +3243,10 @@ static void vmx_set_efer(struct kvm_vcpu *vcpu, u64 efer)
vmx_load_host_state(to_vmx(vcpu));
vcpu->arch.efer = efer;
if (efer & EFER_LMA) {
- vmcs_write32(VM_ENTRY_CONTROLS,
- vmcs_read32(VM_ENTRY_CONTROLS) |
- VM_ENTRY_IA32E_MODE);
+ vm_entry_controls_setbit(to_vmx(vcpu), VM_ENTRY_IA32E_MODE);
msr->data = efer;
} else {
- vmcs_write32(VM_ENTRY_CONTROLS,
- vmcs_read32(VM_ENTRY_CONTROLS) &
- ~VM_ENTRY_IA32E_MODE);
+ vm_entry_controls_clearbit(to_vmx(vcpu), VM_ENTRY_IA32E_MODE);
msr->data = efer & ~EFER_LME;
}
@@ -3217,9 +3274,7 @@ static void enter_lmode(struct kvm_vcpu *vcpu)
static void exit_lmode(struct kvm_vcpu *vcpu)
{
- vmcs_write32(VM_ENTRY_CONTROLS,
- vmcs_read32(VM_ENTRY_CONTROLS)
- & ~VM_ENTRY_IA32E_MODE);
+ vm_entry_controls_clearbit(to_vmx(vcpu), VM_ENTRY_IA32E_MODE);
vmx_set_efer(vcpu, vcpu->arch.efer & ~EFER_LMA);
}
@@ -4346,10 +4401,11 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
++vmx->nmsrs;
}
- vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl);
+
+ vm_exit_controls_init(vmx, vmcs_config.vmexit_ctrl);
/* 22.2.1, 20.8.1 */
- vmcs_write32(VM_ENTRY_CONTROLS, vmcs_config.vmentry_ctrl);
+ vm_entry_controls_init(vmx, vmcs_config.vmentry_ctrl);
vmcs_writel(CR0_GUEST_HOST_MASK, ~0UL);
set_cr4_guest_host_mask(vmx);
@@ -7759,12 +7815,12 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
exit_control = vmcs_config.vmexit_ctrl;
if (vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER)
exit_control |= VM_EXIT_SAVE_VMX_PREEMPTION_TIMER;
- vmcs_write32(VM_EXIT_CONTROLS, exit_control);
+ vm_exit_controls_init(vmx, exit_control);
/* vmcs12's VM_ENTRY_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE are
* emulated by vmx_set_efer(), below.
*/
- vmcs_write32(VM_ENTRY_CONTROLS,
+ vm_entry_controls_init(vmx,
(vmcs12->vm_entry_controls & ~VM_ENTRY_LOAD_IA32_EFER &
~VM_ENTRY_IA32E_MODE) |
(vmcs_config.vmentry_ctrl & ~VM_ENTRY_IA32E_MODE));
@@ -8186,7 +8242,7 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
vmcs12->vm_entry_controls =
(vmcs12->vm_entry_controls & ~VM_ENTRY_IA32E_MODE) |
- (vmcs_read32(VM_ENTRY_CONTROLS) & VM_ENTRY_IA32E_MODE);
+ (vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE);
/* TODO: These cannot have changed unless we have MSR bitmaps and
* the relevant bit asks not to trap the change */
@@ -8390,6 +8446,7 @@ static void nested_vmx_vmexit(struct kvm_vcpu *vcpu)
vcpu->cpu = cpu;
put_cpu();
+ vm_entry_controls_init(vmx, vmcs_read32(VM_ENTRY_CONTROLS));
vmx_segment_cache_clear(vmx);
/* if no vmcs02 cache requested, remove the one we used */
--
Gleb.
--
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