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| author | Gleb Natapov <gleb@redhat.com> | 2010-03-18 15:20:26 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-05-17 12:16:29 +0300 |
| commit | 5cd21917da245fbe98bd443de2c7f519b3df6814 (patch) | |
| tree | 0bb2d4ee197011a92002a5cc32d19758a1e87ed0 /arch/x86/kvm/x86.c | |
| parent | cb404fe0898779ec5fe5e06e90aaddcf40aefad8 (diff) | |
| download | lwn-5cd21917da245fbe98bd443de2c7f519b3df6814.tar.gz lwn-5cd21917da245fbe98bd443de2c7f519b3df6814.zip | |
KVM: x86 emulator: restart string instruction without going back to a guest.
Currently when string instruction is only partially complete we go back
to a guest mode, guest tries to reexecute instruction and exits again
and at this point emulation continues. Avoid all of this by restarting
instruction without going back to a guest mode, but return to a guest
mode each 1024 iterations to allow interrupt injection. Pending
exception causes immediate guest entry too.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 658e8e8155cb..c88cb8145283 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3755,6 +3755,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, return EMULATE_DONE; } +restart: r = x86_emulate_insn(&vcpu->arch.emulate_ctxt, &emulate_ops); shadow_mask = vcpu->arch.emulate_ctxt.interruptibility; @@ -3777,7 +3778,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, if (r) { if (kvm_mmu_unprotect_page_virt(vcpu, cr2)) - return EMULATE_DONE; + goto done; if (!vcpu->mmio_needed) { kvm_report_emulation_failure(vcpu, "mmio"); return EMULATE_FAIL; @@ -3792,6 +3793,13 @@ int emulate_instruction(struct kvm_vcpu *vcpu, return EMULATE_DO_MMIO; } +done: + if (vcpu->arch.exception.pending) + vcpu->arch.emulate_ctxt.restart = false; + + if (vcpu->arch.emulate_ctxt.restart) + goto restart; + return EMULATE_DONE; } EXPORT_SYMBOL_GPL(emulate_instruction); @@ -4560,6 +4568,15 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) goto out; } } + if (vcpu->arch.emulate_ctxt.restart) { + vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); + r = emulate_instruction(vcpu, 0, 0, EMULTYPE_NO_DECODE); + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); + if (r == EMULATE_DO_MMIO) { + r = 0; + goto out; + } + } if (kvm_run->exit_reason == KVM_EXIT_HYPERCALL) kvm_register_write(vcpu, VCPU_REGS_RAX, kvm_run->hypercall.ret); |