[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 19/23] kvm: Unconditionally reenter kernel after IO
From: |
Marcelo Tosatti |
Subject: |
[Qemu-devel] [PATCH 19/23] kvm: Unconditionally reenter kernel after IO exits |
Date: |
Fri, 4 Feb 2011 13:47:22 -0200 |
From: Jan Kiszka <address@hidden>
KVM requires to reenter the kernel after IO exits in order to complete
instruction emulation. Failing to do so will leave the kernel state
inconsistently behind. To ensure that we will get back ASAP, we issue a
self-signal that will cause KVM_RUN to return once the pending
operations are completed.
We can move kvm_arch_process_irqchip_events out of the inner VCPU loop.
The only state that mattered at its old place was a pending INIT
request. Catch it in kvm_arch_pre_run and also trigger a self-signal to
process the request on next kvm_cpu_exec.
This patch also fixes the missing exit_request check in kvm_cpu_exec in
the CONFIG_IOTHREAD case.
Signed-off-by: Jan Kiszka <address@hidden>
CC: Gleb Natapov <address@hidden>
Signed-off-by: Marcelo Tosatti <address@hidden>
---
kvm-all.c | 31 +++++++++++++++++--------------
target-i386/kvm.c | 5 +++++
2 files changed, 22 insertions(+), 14 deletions(-)
diff --git a/kvm-all.c b/kvm-all.c
index a83aff2..0c20f9e 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -199,7 +199,6 @@ int kvm_pit_in_kernel(void)
return kvm_state->pit_in_kernel;
}
-
int kvm_init_vcpu(CPUState *env)
{
KVMState *s = kvm_state;
@@ -896,29 +895,33 @@ int kvm_cpu_exec(CPUState *env)
DPRINTF("kvm_cpu_exec()\n");
- do {
-#ifndef CONFIG_IOTHREAD
- if (env->exit_request) {
- DPRINTF("interrupt exit requested\n");
- ret = 0;
- break;
- }
-#endif
-
- if (kvm_arch_process_irqchip_events(env)) {
- ret = 0;
- break;
- }
+ if (kvm_arch_process_irqchip_events(env)) {
+ env->exit_request = 0;
+ env->exception_index = EXCP_HLT;
+ return 0;
+ }
+ do {
if (env->kvm_vcpu_dirty) {
kvm_arch_put_registers(env, KVM_PUT_RUNTIME_STATE);
env->kvm_vcpu_dirty = 0;
}
kvm_arch_pre_run(env, run);
+ if (env->exit_request) {
+ DPRINTF("interrupt exit requested\n");
+ /*
+ * KVM requires us to reenter the kernel after IO exits to complete
+ * instruction emulation. This self-signal will ensure that we
+ * leave ASAP again.
+ */
+ qemu_cpu_kick_self();
+ }
cpu_single_env = NULL;
qemu_mutex_unlock_iothread();
+
ret = kvm_vcpu_ioctl(env, KVM_RUN, 0);
+
qemu_mutex_lock_iothread();
cpu_single_env = env;
kvm_arch_post_run(env, run);
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 9df8ff8..8a87244 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -1426,6 +1426,11 @@ int kvm_arch_get_registers(CPUState *env)
int kvm_arch_pre_run(CPUState *env, struct kvm_run *run)
{
+ /* Force the VCPU out of its inner loop to process the INIT request */
+ if (env->interrupt_request & CPU_INTERRUPT_INIT) {
+ env->exit_request = 1;
+ }
+
/* Inject NMI */
if (env->interrupt_request & CPU_INTERRUPT_NMI) {
env->interrupt_request &= ~CPU_INTERRUPT_NMI;
--
1.7.2.3
- [Qemu-devel] [PATCH 00/23] [PULL] qemu-kvm.git uq/master queue, Marcelo Tosatti, 2011/02/04
- [Qemu-devel] [PATCH 19/23] kvm: Unconditionally reenter kernel after IO exits,
Marcelo Tosatti <=
- [Qemu-devel] [PATCH 18/23] Introduce VCPU self-signaling service, Marcelo Tosatti, 2011/02/04
- [Qemu-devel] [PATCH 07/23] kvm: Report proper error on GET_VCPU_MMAP_SIZE failures, Marcelo Tosatti, 2011/02/04
- [Qemu-devel] [PATCH 23/23] kvm: make tsc stable over migration and machine start, Marcelo Tosatti, 2011/02/04
- [Qemu-devel] [PATCH 13/23] kvm: Refactor qemu_kvm_eat_signals, Marcelo Tosatti, 2011/02/04
- [Qemu-devel] [PATCH 21/23] kvm: Leave kvm_cpu_exec directly after KVM_EXIT_SHUTDOWN, Marcelo Tosatti, 2011/02/04
- [Qemu-devel] [PATCH 22/23] x86: Fix MCA broadcast parameters for TCG case, Marcelo Tosatti, 2011/02/04
- [Qemu-devel] [PATCH 08/23] kvm: Drop redundant kvm_enabled from kvm_cpu_thread_fn, Marcelo Tosatti, 2011/02/04
- [Qemu-devel] [PATCH 16/23] kvm: Fix race between timer signals and vcpu entry under !IOTHREAD, Marcelo Tosatti, 2011/02/04