Revert "KVM: SVM: Accelerate nested SVM by emulating parts of GIF=0"
This reverts commit 037b6e2531d844994cf79bd4190853427c6af2ac (and
7b8052aecd9c533661493d1140cbec0e1ab311d3 as well). It causes hangs.
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 6577934..f53be7e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -78,11 +78,6 @@
void *arg2, void *opaque);
static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
bool has_error_code, u32 error_code);
-static int vmload_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run);
-static int vmsave_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run);
-static int vmrun_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run);
-static int stgi_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run);
-
static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu)
{
@@ -1496,50 +1491,6 @@
nested_svm_exit_handled_real);
}
-static int nested_svm_emulate(struct vcpu_svm *svm, struct kvm_run *kvm_run)
-{
- int er;
- u32 opcode = 0;
- unsigned long rip;
- unsigned long rip_linear;
-
- svm->vmcb->save.rax = svm->vcpu.arch.regs[VCPU_REGS_RAX];
- svm->vmcb->save.rsp = svm->vcpu.arch.regs[VCPU_REGS_RSP];
- svm->vmcb->save.rip = svm->vcpu.arch.regs[VCPU_REGS_RIP];
- rip = svm->vcpu.arch.regs[VCPU_REGS_RIP];
- rip_linear = rip + svm_seg(&svm->vcpu, VCPU_SREG_CS)->base;
-
- er = emulator_read_std(rip_linear, (void *)&opcode, 3, &svm->vcpu);
- if (er != X86EMUL_CONTINUE)
- return er;
- er = EMULATE_FAIL;
-
- switch (opcode) {
- case 0xda010f:
- vmload_interception(svm, kvm_run);
- er = EMULATE_DONE;
- break;
- case 0xd8010f:
- vmrun_interception(svm, kvm_run);
- er = EMULATE_DONE;
- break;
- case 0xdb010f:
- vmsave_interception(svm, kvm_run);
- er = EMULATE_DONE;
- break;
- case 0xdc010f:
- stgi_interception(svm, kvm_run);
- er = EMULATE_DONE;
- break;
- default:
- nsvm_printk("NSVM: Opcode %x unknown\n", opcode);
- }
-
- nsvm_printk("NSVM: svm emul at 0x%lx -> %d\n", rip, er);
-
- return er;
-}
-
static int nested_svm_vmexit_real(struct vcpu_svm *svm, void *arg1,
void *arg2, void *opaque)
{
@@ -1635,9 +1586,6 @@
kvm_mmu_reset_context(&svm->vcpu);
kvm_mmu_load(&svm->vcpu);
- /* KVM calls vmsave after vmrun, so let's run it now if we can */
- nested_svm_emulate(svm, NULL);
-
return 0;
}
@@ -1848,8 +1796,6 @@
static int clgi_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
{
- int loopcount = 0;
-
if (nested_svm_check_permissions(svm))
return 1;
@@ -1862,23 +1808,6 @@
svm_clear_vintr(svm);
svm->vmcb->control.int_ctl &= ~V_IRQ_MASK;
- /* Let's try to emulate as many instructions as possible in GIF=0 */
-
- while (++loopcount < 100) {
- int er;
-
- er = emulate_instruction(&svm->vcpu, kvm_run, 0, 0, 0);
- nsvm_printk("NSVM: emulating at 0x%lx -> %d\n", svm->vcpu.arch.regs[VCPU_REGS_RIP], er);
-
- /* So we can now emulate the SVM instructions that most probably
- occur at the end of the codepath */
- if (er != EMULATE_DONE) {
- while (true)
- if (nested_svm_emulate(svm, kvm_run) == EMULATE_FAIL)
- break;
- break;
- }
- }
return 1;
}
