Re: [PATCH v2] x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested

2018-01-26 Thread Michael S. Tsirkin
On Thu, Jan 25, 2018 at 04:37:07PM +0100, Vitaly Kuznetsov wrote: > I was investigating an issue with seabios >= 1.10 which stopped working > for nested KVM on Hyper-V. The problem appears to be in > handle_ept_violation() function: when we do fast mmio we need to skip > the instruction so we do

Re: [PATCH v2] x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested

2018-01-26 Thread Michael S. Tsirkin
On Thu, Jan 25, 2018 at 04:37:07PM +0100, Vitaly Kuznetsov wrote: > I was investigating an issue with seabios >= 1.10 which stopped working > for nested KVM on Hyper-V. The problem appears to be in > handle_ept_violation() function: when we do fast mmio we need to skip > the instruction so we do

Re: [PATCH v2] x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested

2018-01-25 Thread Radim Krčmář
2018-01-25 19:16+0200, Michael S. Tsirkin: > On Thu, Jan 25, 2018 at 04:37:07PM +0100, Vitaly Kuznetsov wrote: > > I was investigating an issue with seabios >= 1.10 which stopped working > > for nested KVM on Hyper-V. The problem appears to be in > > handle_ept_violation() function: when we do

Re: [PATCH v2] x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested

2018-01-25 Thread Radim Krčmář
2018-01-25 19:16+0200, Michael S. Tsirkin: > On Thu, Jan 25, 2018 at 04:37:07PM +0100, Vitaly Kuznetsov wrote: > > I was investigating an issue with seabios >= 1.10 which stopped working > > for nested KVM on Hyper-V. The problem appears to be in > > handle_ept_violation() function: when we do

Re: [PATCH v2] x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested

2018-01-25 Thread Michael S. Tsirkin
On Thu, Jan 25, 2018 at 04:37:07PM +0100, Vitaly Kuznetsov wrote: > I was investigating an issue with seabios >= 1.10 which stopped working > for nested KVM on Hyper-V. The problem appears to be in > handle_ept_violation() function: when we do fast mmio we need to skip > the instruction so we do

Re: [PATCH v2] x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested

2018-01-25 Thread Michael S. Tsirkin
On Thu, Jan 25, 2018 at 04:37:07PM +0100, Vitaly Kuznetsov wrote: > I was investigating an issue with seabios >= 1.10 which stopped working > for nested KVM on Hyper-V. The problem appears to be in > handle_ept_violation() function: when we do fast mmio we need to skip > the instruction so we do

[PATCH v2] x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested

2018-01-25 Thread Vitaly Kuznetsov
I was investigating an issue with seabios >= 1.10 which stopped working for nested KVM on Hyper-V. The problem appears to be in handle_ept_violation() function: when we do fast mmio we need to skip the instruction so we do kvm_skip_emulated_instruction(). This, however, depends on

[PATCH v2] x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested

2018-01-25 Thread Vitaly Kuznetsov
I was investigating an issue with seabios >= 1.10 which stopped working for nested KVM on Hyper-V. The problem appears to be in handle_ept_violation() function: when we do fast mmio we need to skip the instruction so we do kvm_skip_emulated_instruction(). This, however, depends on