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authorAnthony Liguori <aliguori@us.ibm.com>2012-08-29 09:32:41 -0500
committerAnthony Liguori <aliguori@us.ibm.com>2012-08-29 10:51:20 -0500
commitef8621b1a3b199c348606c0a11a77d8e8bf135f1 (patch)
treeddf2e6eee35204829d3fc0be0e5523220ed36bb6
parent4d09d37c6aa9a02b44b1fdb6268820fab92499bd (diff)
downloadqemu-arm-ef8621b1a3b199c348606c0a11a77d8e8bf135f1.tar.gz
target-i386: disable pv eoi to fix migration across QEMU versions
We have a problem with how we handle migration with KVM paravirt features. We unconditionally enable paravirt features regardless of whether we know how to migrate them. We also don't tie paravirt features to specific machine types so an old QEMU on a new kernel would expose features that never existed. The 1.2 cycle is over and as things stand, migration is broken. Michael has another series that adds support for migrating PV EOI and attempts to make it work correctly for different machine types. After speaking with Michael on IRC, we agreed to take this patch plus 1 & 4 from his series. This makes sure QEMU can migrate PV EOI if it's enabled, but does not enable it by default. This also means that we won't unconditionally enable new features for guests future proofing us from this happening again in the future. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
-rw-r--r--target-i386/cpu.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 120a2e3d3e..f3cac49fd3 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -33,6 +33,7 @@
#include "hyperv.h"
#include "hw/hw.h"
+#include <linux/kvm_para.h>
/* feature flags taken from "Intel Processor Identification and the CPUID
* Instruction" and AMD's "CPUID Specification". In cases of disagreement
@@ -887,7 +888,17 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
memcpy(x86_cpu_def, def, sizeof(*def));
}
- plus_kvm_features = ~0; /* not supported bits will be filtered out later */
+#if defined(CONFIG_KVM)
+ plus_kvm_features = (1 << KVM_FEATURE_CLOCKSOURCE) |
+ (1 << KVM_FEATURE_NOP_IO_DELAY) |
+ (1 << KVM_FEATURE_MMU_OP) |
+ (1 << KVM_FEATURE_CLOCKSOURCE2) |
+ (1 << KVM_FEATURE_ASYNC_PF) |
+ (1 << KVM_FEATURE_STEAL_TIME) |
+ (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT);
+#else
+ plus_kvm_features = 0;
+#endif
add_flagname_to_bitmaps("hypervisor", &plus_features,
&plus_ext_features, &plus_ext2_features, &plus_ext3_features,