Gleb Natapov wrote: > On Wed, Dec 09, 2009 at 07:23:38PM +0100, Jan Kiszka wrote: >> Marcelo Tosatti wrote: >>> Otherwise a zero apic base is loaded into KVM, which results >>> in interrupts being lost until a proper apic base with enabled >>> bit set is loaded. >>> >>> Fixes WinXP migration in qemu-kvm origin/next. >>> >>> Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx> >>> >>> diff --git a/hw/apic.c b/hw/apic.c >>> index 627ff98..45a4d2b 100644 >>> --- a/hw/apic.c >>> +++ b/hw/apic.c >>> @@ -1131,6 +1131,11 @@ int apic_init(CPUState *env) >>> vmstate_register(s->idx, &vmstate_apic, s); >>> qemu_register_reset(apic_reset, s); >>> >>> + /* apic_reset must be called before the vcpu threads are initialized and load >>> + * registers, in qemu-kvm. >>> + */ >>> + apic_reset(s); >>> + >>> local_apics[s->idx] = s; >>> return 0; >>> } >> Heals the issue I saw with Win2003 Server as well. >> >> Looks all a bit messy though. Hope we can establish a more regular and >> less fragile model on the midterm. I wonder if it wouldn't be better to >> do write-back of the local APIC state along with the register state on >> vmrun (and only there!). The same would apply to things like mpstate, > Write back of mp state there is a bug and introduce races. Do write back > of the whole APIC state there looks like a recipe for disaster. Please read the full suggestion: We will only write-back if we were going through a reset or vmload before. That removes the ugly kvm hooks from generic code and ensures proper ordering /wrt other write-backs. IMHO, anything else will continue to cause headache like the above to us. Jan > >> TSC MSR, or the guest debugging state. The reset/vmloading/hw-emulation >> code would only declare what kind of write-back it wishes: register >> state only, partial (excluding everything that touches continuously >> running timers), full. Well, basically the model I suggested for proper >> mpstate write-back, just even more generalized. >> >> Jan >> >> -- >> Siemens AG, Corporate Technology, CT T DE IT 1 >> Corporate Competence Center Embedded Linux
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