diff options
| author | Gleb Natapov <gleb@redhat.com> | 2010-04-28 19:15:29 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-08-01 10:35:31 +0300 |
| commit | 5951c4423724759906b10a26aa6a8817c4afa615 (patch) | |
| tree | 552b885e950cf61e841534cbefd0231f9ad0992d | |
| parent | 3fb1b5dbd397d16a855c97c3fb80fe6e9196ce7c (diff) | |
KVM: x86 emulator: add get_cached_segment_base() callback to x86_emulate_ops
On VMX it is expensive to call get_cached_descriptor() just to get segment
base since multiple vmcs_reads are done instead of only one. Introduce
new call back get_cached_segment_base() for efficiency.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
| -rw-r--r-- | arch/x86/include/asm/kvm_emulate.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/emulate.c | 13 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 7 |
3 files changed, 9 insertions, 12 deletions
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index f751657be732..df53ba2294b6 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -132,6 +132,7 @@ struct x86_emulate_ops { int seg, struct kvm_vcpu *vcpu); u16 (*get_segment_selector)(int seg, struct kvm_vcpu *vcpu); void (*set_segment_selector)(u16 sel, int seg, struct kvm_vcpu *vcpu); + unsigned long (*get_cached_segment_base)(int seg, struct kvm_vcpu *vcpu); void (*get_gdt)(struct desc_ptr *dt, struct kvm_vcpu *vcpu); ulong (*get_cr)(int cr, struct kvm_vcpu *vcpu); void (*set_cr)(int cr, ulong val, struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 7c8ed560fd41..8228778ace38 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2097,17 +2097,6 @@ static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt, return true; } -static u32 get_cached_descriptor_base(struct x86_emulate_ctxt *ctxt, - struct x86_emulate_ops *ops, - int seg) -{ - struct desc_struct desc; - if (ops->get_cached_descriptor(&desc, seg, ctxt->vcpu)) - return get_desc_base(&desc); - else - return ~0; -} - static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, struct tss_segment_16 *tss) @@ -2383,7 +2372,7 @@ static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, int ret; u16 old_tss_sel = ops->get_segment_selector(VCPU_SREG_TR, ctxt->vcpu); ulong old_tss_base = - get_cached_descriptor_base(ctxt, ops, VCPU_SREG_TR); + ops->get_cached_segment_base(VCPU_SREG_TR, ctxt->vcpu); u32 desc_limit; /* FIXME: old_tss_base == ~0 ? */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e3a5455049b0..9a469df6011c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3714,6 +3714,12 @@ static void emulator_get_gdt(struct desc_ptr *dt, struct kvm_vcpu *vcpu) kvm_x86_ops->get_gdt(vcpu, dt); } +static unsigned long emulator_get_cached_segment_base(int seg, + struct kvm_vcpu *vcpu) +{ + return get_segment_base(vcpu, seg); +} + static bool emulator_get_cached_descriptor(struct desc_struct *desc, int seg, struct kvm_vcpu *vcpu) { @@ -3804,6 +3810,7 @@ static struct x86_emulate_ops emulate_ops = { .set_cached_descriptor = emulator_set_cached_descriptor, .get_segment_selector = emulator_get_segment_selector, .set_segment_selector = emulator_set_segment_selector, + .get_cached_segment_base = emulator_get_cached_segment_base, .get_gdt = emulator_get_gdt, .get_cr = emulator_get_cr, .set_cr = emulator_set_cr, |