[PATCH 02/21] kvm/svm: optimize nested #vmexit

From: Joerg Roedel
Date: Fri Aug 07 2009 - 05:51:52 EST


It is more efficient to copy only the relevant parts of the vmcb back to
the nested vmcb when we emulate an vmexit.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
Acked-by: Alexander Graf <agraf@xxxxxxx>
---
arch/x86/kvm/svm.c | 68 +++++++++++++++++++++++++--------------------------
1 files changed, 33 insertions(+), 35 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 8eb0852..02ebc3f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1575,53 +1575,52 @@ static int nested_svm_vmexit_real(struct vcpu_svm *svm, void *arg1,
{
struct vmcb *nested_vmcb = (struct vmcb *)arg1;
struct vmcb *hsave = svm->hsave;
- u64 nested_save[] = { nested_vmcb->save.cr0,
- nested_vmcb->save.cr3,
- nested_vmcb->save.cr4,
- nested_vmcb->save.efer,
- nested_vmcb->control.intercept_cr_read,
- nested_vmcb->control.intercept_cr_write,
- nested_vmcb->control.intercept_dr_read,
- nested_vmcb->control.intercept_dr_write,
- nested_vmcb->control.intercept_exceptions,
- nested_vmcb->control.intercept,
- nested_vmcb->control.msrpm_base_pa,
- nested_vmcb->control.iopm_base_pa,
- nested_vmcb->control.tsc_offset };
+ struct vmcb *vmcb = svm->vmcb;

/* Give the current vmcb to the guest */
- memcpy(nested_vmcb, svm->vmcb, sizeof(struct vmcb));
- nested_vmcb->save.cr0 = nested_save[0];
- if (!npt_enabled)
- nested_vmcb->save.cr3 = nested_save[1];
- nested_vmcb->save.cr4 = nested_save[2];
- nested_vmcb->save.efer = nested_save[3];
- nested_vmcb->control.intercept_cr_read = nested_save[4];
- nested_vmcb->control.intercept_cr_write = nested_save[5];
- nested_vmcb->control.intercept_dr_read = nested_save[6];
- nested_vmcb->control.intercept_dr_write = nested_save[7];
- nested_vmcb->control.intercept_exceptions = nested_save[8];
- nested_vmcb->control.intercept = nested_save[9];
- nested_vmcb->control.msrpm_base_pa = nested_save[10];
- nested_vmcb->control.iopm_base_pa = nested_save[11];
- nested_vmcb->control.tsc_offset = nested_save[12];
+ disable_gif(svm);
+
+ nested_vmcb->save.es = vmcb->save.es;
+ nested_vmcb->save.cs = vmcb->save.cs;
+ nested_vmcb->save.ss = vmcb->save.ss;
+ nested_vmcb->save.ds = vmcb->save.ds;
+ nested_vmcb->save.gdtr = vmcb->save.gdtr;
+ nested_vmcb->save.idtr = vmcb->save.idtr;
+ if (npt_enabled)
+ nested_vmcb->save.cr3 = vmcb->save.cr3;
+ nested_vmcb->save.cr2 = vmcb->save.cr2;
+ nested_vmcb->save.rflags = vmcb->save.rflags;
+ nested_vmcb->save.rip = vmcb->save.rip;
+ nested_vmcb->save.rsp = vmcb->save.rsp;
+ nested_vmcb->save.rax = vmcb->save.rax;
+ nested_vmcb->save.dr7 = vmcb->save.dr7;
+ nested_vmcb->save.dr6 = vmcb->save.dr6;
+ nested_vmcb->save.cpl = vmcb->save.cpl;
+
+ nested_vmcb->control.int_ctl = vmcb->control.int_ctl;
+ nested_vmcb->control.int_vector = vmcb->control.int_vector;
+ nested_vmcb->control.int_state = vmcb->control.int_state;
+ nested_vmcb->control.exit_code = vmcb->control.exit_code;
+ nested_vmcb->control.exit_code_hi = vmcb->control.exit_code_hi;
+ nested_vmcb->control.exit_info_1 = vmcb->control.exit_info_1;
+ nested_vmcb->control.exit_info_2 = vmcb->control.exit_info_2;
+ nested_vmcb->control.exit_int_info = vmcb->control.exit_int_info;
+ nested_vmcb->control.exit_int_info_err = vmcb->control.exit_int_info_err;
+ nested_vmcb->control.tlb_ctl = 0;
+ nested_vmcb->control.event_inj = 0;
+ nested_vmcb->control.event_inj_err = 0;

/* We always set V_INTR_MASKING and remember the old value in hflags */
if (!(svm->vcpu.arch.hflags & HF_VINTR_MASK))
nested_vmcb->control.int_ctl &= ~V_INTR_MASKING_MASK;

- if ((nested_vmcb->control.int_ctl & V_IRQ_MASK) &&
- (nested_vmcb->control.int_vector)) {
- nsvm_printk("WARNING: IRQ 0x%x still enabled on #VMEXIT\n",
- nested_vmcb->control.int_vector);
- }
-
/* Restore the original control entries */
svm->vmcb->control = hsave->control;

/* Kill any pending exceptions */
if (svm->vcpu.arch.exception.pending == true)
nsvm_printk("WARNING: Pending Exception\n");
+
kvm_clear_exception_queue(&svm->vcpu);
kvm_clear_interrupt_queue(&svm->vcpu);

@@ -1649,7 +1648,6 @@ static int nested_svm_vmexit_real(struct vcpu_svm *svm, void *arg1,
svm->vmcb->save.cpl = 0;
svm->vmcb->control.exit_int_info = 0;

- disable_gif(svm);
/* Exit nested SVM mode */
svm->nested_vmcb = 0;

--
1.6.3.3


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