Re: [PATCH 1/2] kvm: Fix x86 emulator writeback

2007-06-20 Thread Avi Kivity
Luca Tettamanti wrote: > When the old value and new one are the same the emulator skips the > write; this is undesiderable when the destination is a MMIO area and the > write shall be performed regardless of the previous value. This > optimization breaks e.g. a Linux guest APIC compiled without > X

[PATCH 1/2] kvm: Fix x86 emulator writeback

2007-06-19 Thread Luca Tettamanti
When the old value and new one are the same the emulator skips the write; this is undesiderable when the destination is a MMIO area and the write shall be performed regardless of the previous value. This optimization breaks e.g. a Linux guest APIC compiled without X86_GOOD_APIC. Remove the check a

Re: [PATCH 1/2] kvm: Fix x86 emulator writeback

2007-06-19 Thread Luca Tettamanti
Il Mon, Jun 18, 2007 at 02:32:39PM +0300, Avi Kivity ha scritto: > >Unfortunately, this kills Windows XP (first run with a guest crash, > >second with a host oops), so I reverted it. I'd guess some operation > >which doesn't need writeback ends up in the modified code. > >Previously, the che

Re: [PATCH 1/2] kvm: Fix x86 emulator writeback

2007-06-18 Thread Avi Kivity
Avi Kivity wrote: Luca Tettamanti wrote: When the old value and new one are the same the emulator skips the write; this is undesiderable when the destination is a MMIO area and the write shall be performed regardless of the previous value. This optimization breaks e.g. a Linux guest APIC compile

Re: [PATCH 1/2] kvm: Fix x86 emulator writeback

2007-06-18 Thread Avi Kivity
Luca Tettamanti wrote: When the old value and new one are the same the emulator skips the write; this is undesiderable when the destination is a MMIO area and the write shall be performed regardless of the previous value. This optimization breaks e.g. a Linux guest APIC compiled without X86_GOOD_

Re: [PATCH 1/2] kvm: Fix x86 emulator writeback

2007-06-17 Thread Avi Kivity
Luca Tettamanti wrote: When the old value and new one are the same the emulator skips the write; this is undesiderable when the destination is a MMIO area and the write shall be performed regardless of the previous value. This optimization breaks e.g. a Linux guest APIC compiled without X86_GOOD_

[PATCH 1/2] kvm: Fix x86 emulator writeback

2007-06-17 Thread Luca Tettamanti
When the old value and new one are the same the emulator skips the write; this is undesiderable when the destination is a MMIO area and the write shall be performed regardless of the previous value. This optimization breaks e.g. a Linux guest APIC compiled without X86_GOOD_APIC. Remove the check a