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* [Qemu-devel] [PATCH] target/i386: kvm: Fix when nested state is needed for migration
@ 2019-06-24 23:05 Liran Alon
  2019-07-02 16:39 ` Paolo Bonzini
  0 siblings, 1 reply; 5+ messages in thread
From: Liran Alon @ 2019-06-24 23:05 UTC (permalink / raw)
  To: qemu-devel; +Cc: pbonzini, Liran Alon, Karl Heubaum, kvm

When vCPU is in VMX operation and enters SMM mode,
it temporarily exits VMX operation but KVM maintained nested-state
still stores the VMXON region physical address, i.e. even when the
vCPU is in SMM mode then (nested_state->hdr.vmx.vmxon_pa != -1ull).

Therefore, there is no need to explicitly check for
KVM_STATE_NESTED_SMM_VMXON to determine if it is necessary
to save nested-state as part of migration stream.

In addition, destination must enable eVMCS if it is enabled on
source as specified by the KVM_STATE_NESTED_EVMCS flag, even if
the VMXON region is not set. Thus, change the code to require saving
nested-state as part of migration stream in case it is set.

Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
---
 target/i386/machine.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/i386/machine.c b/target/i386/machine.c
index 851b249d1a39..e7d72faf9e24 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -999,7 +999,7 @@ static bool vmx_nested_state_needed(void *opaque)
 
     return ((nested_state->format == KVM_STATE_NESTED_FORMAT_VMX) &&
             ((nested_state->hdr.vmx.vmxon_pa != -1ull) ||
-             (nested_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON)));
+             (nested_state->flags & KVM_STATE_NESTED_EVMCS)));
 }
 
 static const VMStateDescription vmstate_vmx_nested_state = {
-- 
2.20.1



^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2019-07-04 15:37 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-06-24 23:05 [Qemu-devel] [PATCH] target/i386: kvm: Fix when nested state is needed for migration Liran Alon
2019-07-02 16:39 ` Paolo Bonzini
2019-07-04 14:31   ` Liran Alon
2019-07-04 15:29     ` Paolo Bonzini
2019-07-04 15:34       ` Liran Alon

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