[PATCH 0/3] kvm: APICv register write workaround

From: Radim KrÄmÃÅ
Date: Thu Oct 30 2014 - 10:08:52 EST


APICv traps register writes, so we can't retrieve previous value, but
our code depends on detecting changes.

Apart from disabling APIC register virtualization, we can detect the
change by using extra memory. One value history is enough, but we still
don't want to keep it for every APIC register, for performance reasons.
This leaves us with either a new framework, or exceptions ...
The latter options fits KVM's path better [1,2].

And when we already mirror a part of registers, optimizing access is
acceptable [3]. (Squashed to keep bisecters happy.)

---
Radim KrÄmÃÅ (3):
KVM: x86: detect SPIV changes under APICv
KVM: x86: detect LVTT changes under APICv
KVM: x86: optimize some accesses to LVTT and SPIV

arch/x86/kvm/lapic.c | 32 +++++++++++++++++---------------
arch/x86/kvm/lapic.h | 8 +++++---
2 files changed, 22 insertions(+), 18 deletions(-)

--
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/