From: Alexis Dambricourt Date: Mon, 14 Dec 2015 14:39:34 +0000 (+0100) Subject: KVM: MTRR: fix fixed MTRR segment look up X-Git-Tag: v4.4-rc7~15^2~3 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=a7f2d7865720ff13d5b0f2a3bb1fd80dc3d7a73f;p=linux.git KVM: MTRR: fix fixed MTRR segment look up This fixes the slow-down of VM running with pci-passthrough, since some MTRR range changed from MTRR_TYPE_WRBACK to MTRR_TYPE_UNCACHABLE. Memory in the 0K-640K range was incorrectly treated as uncacheable. Fixes: f7bfb57b3e89ff89c0da9f93dedab89f68d6ca27 Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=107561 Cc: qemu-stable@nongnu.org Signed-off-by: Alexis Dambricourt [Use correct BZ for "Fixes" annotation. - Paolo] Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c index 9e8bf13572e6..adc54e1d40a9 100644 --- a/arch/x86/kvm/mtrr.c +++ b/arch/x86/kvm/mtrr.c @@ -267,7 +267,7 @@ static int fixed_mtrr_addr_to_seg(u64 addr) for (seg = 0; seg < seg_num; seg++) { mtrr_seg = &fixed_seg_table[seg]; - if (mtrr_seg->start >= addr && addr < mtrr_seg->end) + if (mtrr_seg->start <= addr && addr < mtrr_seg->end) return seg; }