|
 |
218e99 |
From c576ee9550d38273808c2055803f3a254655753e Mon Sep 17 00:00:00 2001
|
|
|
218e99 |
From: Orit Wasserman <owasserm@redhat.com>
|
|
|
218e99 |
Date: Wed, 9 Oct 2013 10:09:10 +0200
|
|
|
218e99 |
Subject: [PATCH 15/25] Fix real mode guest migration
|
|
|
218e99 |
|
|
|
218e99 |
RH-Author: Orit Wasserman <owasserm@redhat.com>
|
|
|
218e99 |
Message-id: <1381313355-15641-6-git-send-email-owasserm@redhat.com>
|
|
|
218e99 |
Patchwork-id: 54801
|
|
|
218e99 |
O-Subject: [RHEL7.0 qemu-kvm v2 05/10] Fix real mode guest migration
|
|
|
218e99 |
Bugzilla: 921465
|
|
|
218e99 |
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
|
218e99 |
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
|
|
|
218e99 |
RH-Acked-by: Juan Quintela <quintela@redhat.com>
|
|
|
218e99 |
|
|
|
218e99 |
Older KVM versions save CS dpl value to an invalid value for real mode guests
|
|
|
218e99 |
(0x3). This patch detect this situation when loading CPU state and set all the
|
|
|
218e99 |
segments dpl to zero.
|
|
|
218e99 |
This will allow migration from older KVM on host without unrestricted guest
|
|
|
218e99 |
to hosts with restricted guest support.
|
|
|
218e99 |
For example migration from a Penryn host (with kernel 2.6.32) to
|
|
|
218e99 |
a Westmere host (for real mode guest) will fail with "kvm: unhandled exit 80000021".
|
|
|
218e99 |
|
|
|
218e99 |
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
|
|
|
218e99 |
Reviewed-by: Juan Quintela <quintela@redhat.com>
|
|
|
218e99 |
Signed-off-by: Juan Quintela <quintela@redhat.com>
|
|
|
218e99 |
(cherry picked from commit 444ba6797ef6ef331fe9fd34309b1ec59caaede3)
|
|
|
218e99 |
---
|
|
|
218e99 |
target-i386/machine.c | 18 ++++++++++++++++++
|
|
|
218e99 |
1 file changed, 18 insertions(+)
|
|
|
218e99 |
|
|
|
218e99 |
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
218e99 |
---
|
|
|
218e99 |
target-i386/machine.c | 18 ++++++++++++++++++
|
|
|
218e99 |
1 files changed, 18 insertions(+), 0 deletions(-)
|
|
|
218e99 |
|
|
|
218e99 |
diff --git a/target-i386/machine.c b/target-i386/machine.c
|
|
|
218e99 |
index ecf1617..079a132 100644
|
|
|
218e99 |
--- a/target-i386/machine.c
|
|
|
218e99 |
+++ b/target-i386/machine.c
|
|
|
218e99 |
@@ -260,6 +260,24 @@ static int cpu_post_load(void *opaque, int version_id)
|
|
|
218e99 |
CPUX86State *env = &cpu->env;
|
|
|
218e99 |
int i;
|
|
|
218e99 |
|
|
|
218e99 |
+ /*
|
|
|
218e99 |
+ * Real mode guest segments register DPL should be zero.
|
|
|
218e99 |
+ * Older KVM version were setting it wrongly.
|
|
|
218e99 |
+ * Fixing it will allow live migration from such host that don't have
|
|
|
218e99 |
+ * restricted guest support to a host with unrestricted guest support
|
|
|
218e99 |
+ * (otherwise the migration will fail with invalid guest state
|
|
|
218e99 |
+ * error).
|
|
|
218e99 |
+ */
|
|
|
218e99 |
+ if (!(env->cr[0] & CR0_PE_MASK) &&
|
|
|
218e99 |
+ (env->segs[R_CS].flags >> DESC_DPL_SHIFT & 3) != 0) {
|
|
|
218e99 |
+ env->segs[R_CS].flags &= ~(env->segs[R_CS].flags & DESC_DPL_MASK);
|
|
|
218e99 |
+ env->segs[R_DS].flags &= ~(env->segs[R_DS].flags & DESC_DPL_MASK);
|
|
|
218e99 |
+ env->segs[R_ES].flags &= ~(env->segs[R_ES].flags & DESC_DPL_MASK);
|
|
|
218e99 |
+ env->segs[R_FS].flags &= ~(env->segs[R_FS].flags & DESC_DPL_MASK);
|
|
|
218e99 |
+ env->segs[R_GS].flags &= ~(env->segs[R_GS].flags & DESC_DPL_MASK);
|
|
|
218e99 |
+ env->segs[R_SS].flags &= ~(env->segs[R_SS].flags & DESC_DPL_MASK);
|
|
|
218e99 |
+ }
|
|
|
218e99 |
+
|
|
|
218e99 |
/* XXX: restore FPU round state */
|
|
|
218e99 |
env->fpstt = (env->fpus_vmstate >> 11) & 7;
|
|
|
218e99 |
env->fpus = env->fpus_vmstate & ~0x3800;
|
|
|
218e99 |
--
|
|
|
218e99 |
1.7.1
|
|
|
218e99 |
|