I am running into a performance problem in my Windows 10 VFIO setup. One of the games (Heroes of the Storm) which was running fine in Win8.1 stopped working due to unsupported msrs. After enabling ignore_msrs it now runs but with a huge performance penalty. The kernel log if flooded with 1000s of callback suppressed messages from the ignored msrs. The messages that pop up are basically the following vcpu1 ignored rdmsr: 0x1c9 kvm [2129]: vcpu1 ignored rdmsr: 0x680 kvm [2129]: vcpu1 ignored rdmsr: 0x6c0 vcpu2 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop Those appear to be LBR related, enabling and reading the TOS and LBR registers. The problem is these calls seem to be degrading performance, even when ignored. I did find a patch on this mailing list from last November that implemented LBR in KVM, but when I tried the patch the performance was even worse. Is there anyway of solving this issue? Is it possible to handle these LBR reads in KVM efficiently? Thanks, Abdulla -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
