KVM: x86: Ensure runtime reads of disabled_quirks are resolved once

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Wrap the sole reader of disabled_quirks with READ_ONCE(), and wrap the
post-VM-creation write to disabled_quirks with WRITE_ONCE(), to ensure
checking the status of a quirk doesn't re-read disabled_quirks *if* the
caller needs such a guarantee.  This will allow splitting the "fast" MMU
zap into front and back halves, without potentially skipping the back
half if SLOT_ZAP_ALL were concurrently disabled (which would be "fine" in
the current code base, but far from ideal).

Cc: stable@vger.kernel.org # 6.12.x
Reviewed-by: Michael Roth <michael.roth@amd.com>
Link: https://patch.msgid.link/20260709204948.1988414-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

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Sean Christopherson 2026-07-09 13:49:36 -07:00

parent ba76b23ed3

commit ed15cb2199

2 changed files with 3 additions and 2 deletions

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arch/x86/kvm/x86.c

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2

arch/x86/kvm/x86.h

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