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From: Alex Williamson <alex.williamson@redhat.com>
To: qemu-devel@nongnu.org, kvm@vger.kernel.org
Cc: lersek@redhat.com, qemu-stable@nongnu.org
Subject: [Qemu-devel] [PATCH v3 0/3] Sync MTRRs with KVM and disable on reset
Date: Thu, 14 Aug 2014 15:39:21 -0600	[thread overview]
Message-ID: <20140814213751.16881.91600.stgit@gimli.home> (raw)

v3:
 - Fix off-by-one identified by Laszlo in 2/3
 - Add R-b in 1 & 3

It turns out that not only do we not follow the SDM guidelines for
reseting MTRR state on vCPU reset, but we really don't even attempt
to keep KVM MTRR state synchronized with QEMU, which affects not
only reset, but migration.  This series implements the get/put MSR
support for KVM, then goes on to properly re-initialize the state on
vCPU reset.  This resolves the problem described in the last patch
as well as some potential mismatches around migration.  The migration
state is unchanged, other than actually passing valid data.

Thanks to Laszlo for his help debugging this and realization of how
terribly broken MTRR synchronization is.  Thanks,

Alex

---

Alex Williamson (3):
      x86: Clear MTRRs on vCPU reset
      x86: kvm: Add MTRR support for kvm_get|put_msrs()
      x86: Use common variable range MTRR counts


 target-i386/cpu.c     |   10 +++++
 target-i386/cpu.h     |    4 +-
 target-i386/kvm.c     |  101 ++++++++++++++++++++++++++++++++++++++++++++++++-
 target-i386/machine.c |    2 -
 4 files changed, 113 insertions(+), 4 deletions(-)

             reply	other threads:[~2014-08-14 21:39 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-14 21:39 Alex Williamson [this message]
2014-08-14 21:39 ` [Qemu-devel] [PATCH v3 1/3] x86: Use common variable range MTRR counts Alex Williamson
2014-08-14 21:39 ` [Qemu-devel] [PATCH v3 2/3] x86: kvm: Add MTRR support for kvm_get|put_msrs() Alex Williamson
2014-08-14 22:18   ` Laszlo Ersek
2014-08-14 21:39 ` [Qemu-devel] [PATCH v3 3/3] x86: Clear MTRRs on vCPU reset Alex Williamson
2014-08-25 16:49 ` [Qemu-devel] [PATCH v3 0/3] Sync MTRRs with KVM and disable on reset Paolo Bonzini

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