On 07/13/2015 01:33 AM, Alex Williamson wrote:
On Wed, 2015-05-13 at 14:42 +0800, Xiao Guangrong wrote:There are some bugs in current get_mtrr_type(); 1: bit 1 of mtrr_state->enabled is corresponding bit 11 of IA32_MTRR_DEF_TYPE MSR which completely control MTRR's enablement that means other bits are ignored if it is cleared 2: the fixed MTRR ranges are controlled by bit 0 of mtrr_state->enabled (bit 10 of IA32_MTRR_DEF_TYPE) 3: if MTRR is disabled, UC is applied to all of physical memory rather than mtrr_state->def_type Signed-off-by: Xiao Guangrong <[email protected]> --- arch/x86/kvm/mmu.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-)I'm seeing a significant regression in boot performance on Intel hardware with assigned devices that bisects back to this patch. There's a long delay with Seabios between the version splash and execution of option ROMs, and a _very_ long delay with OVMF before the display is initialized. The delay is long enough that users are reporting their previously working VM is hung with 100% CPU usage on v4.2-rc1. Thanks,
Alex, thanks for your report. I will try to reproduce and fix it asap. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
