From patchwork Thu Dec  2 12:56:30 2010
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Subject: [PATCHv3,4/6] virtio-net: stop/start bh when appropriate
From: Jason Wang <jasowang@redhat.com>
X-Patchwork-Id: 73961
Message-Id: <19703.38782.929586.869640@gargle.gargle.HOWL>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>, mtosatti@redhat.com,
 qemu-devel@nongnu.org, quintela@redhat.com
Date: Thu, 2 Dec 2010 20:56:30 +0800

Michael S. Tsirkin writes:
 > On Wed, Dec 01, 2010 at 01:45:09PM +0800, Jason Wang wrote:
 > > Michael S. Tsirkin writes:
 > >  > Avoid sending out packets, and modifying
 > >  > device state, when VM is stopped.
 > >  > Add assert statements to verify this does not happen.
 > >  > 
 > >  > Avoid scheduling bh when vhost-net is started.
 > >  > 
 > >  > Stop bh when driver disabled bus mastering
 > >  > (we must not access memory after this).
 > >  > 
 > >  > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
 > >  > 
 > > 
 > > There's no need to disable it bh we call qemu_aio_flush() after
 > > vm_state_notify() in do_vm_stop(). And for timer, looks like every device should
 > > stop its timer in vm state change handler, not only for virtio-net?
 > 
 > BTW I fixed some typos. Here a fixed version.
 > Jason, could you review/test please?
 > 

Have done the test, it's more stable than before but still get small deltas in
cpu section. I didn't find any interesting difference by checking the
CPUX86State in the dest in kvm_arch_load_regs(), any thought on this?

BTW, looks like the error_code was missed in saving the cpu state:


diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 35a1a51..145bb38 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -687,7 +687,7 @@ typedef struct CPUX86State {
     uint64_t pat;
 
     /* exception/interrupt handling */
-    int error_code;
+    uint32_t error_code;
     int exception_is_int;
     target_ulong exception_next_eip;
     target_ulong dr[8]; /* debug registers */
@@ -935,7 +935,7 @@ CPUState *pc_new_cpu(const char *cpu_model);
 #define cpu_list_id x86_cpu_list
 #define cpudef_setup	x86_cpudef_setup
 
-#define CPU_SAVE_VERSION 12
+#define CPU_SAVE_VERSION 13
 
 /* MMU modes definitions */
 #define MMU_MODE0_SUFFIX _kernel
diff --git a/target-i386/machine.c b/target-i386/machine.c
index 4398801..fa231d8 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -474,6 +474,8 @@ static const VMStateDescription vmstate_cpu = {
         VMSTATE_UINT64_V(xcr0, CPUState, 12),
         VMSTATE_UINT64_V(xstate_bv, CPUState, 12),
         VMSTATE_YMMH_REGS_VARS(ymmh_regs, CPUState, CPU_NB_REGS, 12),
+
+        VMSTATE_UINT32_V(error_code, CPUState, 13),
         VMSTATE_END_OF_LIST()
         /* The above list is not sorted /wrt version numbers, watch out! */
     }