From ef8621b1a3b199c348606c0a11a77d8e8bf135f1 Mon Sep 17 00:00:00 2001 From: Anthony Liguori Date: Wed, 29 Aug 2012 09:32:41 -0500 Subject: 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 --- target-i386/cpu.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 120a2e3d3..f3cac49fd 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -33,6 +33,7 @@ #include "hyperv.h" #include "hw/hw.h" +#include /* 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, -- cgit v1.2.3