[PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-19 Thread Paolo Bonzini
Patches 1 and 2 fix two cases where a guest could hang at 100% CPU due to mis-emulation of a failing invept or invvpid. Patch 3 works around a bug in RHEL6 KVM, which is exposed by nested VPID support; RHEL6 KVM uses single-context invvpid unconditionally, but until now KVM did not provide it.

[PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-19 Thread Paolo Bonzini
Patches 1 and 2 fix two cases where a guest could hang at 100% CPU due to mis-emulation of a failing invept or invvpid. Patch 3 works around a bug in RHEL6 KVM, which is exposed by nested VPID support; RHEL6 KVM uses single-context invvpid unconditionally, but until now KVM did not provide it.

Re: [PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-19 Thread Paolo Bonzini
On 18/03/2016 19:04, David Matlack wrote: > > the tests would effectively DoS the host. > > How does this DoS the host? The guest is stuck executing the same > instruction over and over, but it's exiting to KVM every time, > allowing KVM to reschedule the VCPU. I would agree it DoSes the guest.

Re: [PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-19 Thread Paolo Bonzini
On 18/03/2016 19:04, David Matlack wrote: > > the tests would effectively DoS the host. > > How does this DoS the host? The guest is stuck executing the same > instruction over and over, but it's exiting to KVM every time, > allowing KVM to reschedule the VCPU. I would agree it DoSes the guest.

Re: [PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-18 Thread Paolo Bonzini
On 18/03/2016 18:42, David Matlack wrote: > On Fri, Mar 18, 2016 at 9:09 AM, Paolo Bonzini wrote: >> Patches 1 and 2 fix two cases where a guest could hang at 100% CPU >> due to mis-emulation of a failing invept or invvpid. > > Will you be sending out kvm-unit-test test

Re: [PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-18 Thread Paolo Bonzini
On 18/03/2016 18:42, David Matlack wrote: > On Fri, Mar 18, 2016 at 9:09 AM, Paolo Bonzini wrote: >> Patches 1 and 2 fix two cases where a guest could hang at 100% CPU >> due to mis-emulation of a failing invept or invvpid. > > Will you be sending out kvm-unit-test test cases for these? Yes,

Re: [PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-18 Thread David Matlack
On Fri, Mar 18, 2016 at 9:09 AM, Paolo Bonzini wrote: > Patches 1 and 2 fix two cases where a guest could hang at 100% CPU > due to mis-emulation of a failing invept or invvpid. Will you be sending out kvm-unit-test test cases for these? > > Patch 3 works around a bug in

Re: [PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-18 Thread David Matlack
On Fri, Mar 18, 2016 at 9:09 AM, Paolo Bonzini wrote: > Patches 1 and 2 fix two cases where a guest could hang at 100% CPU > due to mis-emulation of a failing invept or invvpid. Will you be sending out kvm-unit-test test cases for these? > > Patch 3 works around a bug in RHEL6 KVM, which is

Re: [PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-18 Thread David Matlack
On Fri, Mar 18, 2016 at 10:58 AM, Paolo Bonzini wrote: > > > On 18/03/2016 18:42, David Matlack wrote: >> On Fri, Mar 18, 2016 at 9:09 AM, Paolo Bonzini wrote: >>> Patches 1 and 2 fix two cases where a guest could hang at 100% CPU >>> due to

Re: [PATCH 0/3] KVM: VMX: fix handling inv{ept,vpid} and nested RHEL6 KVM

2016-03-18 Thread David Matlack
On Fri, Mar 18, 2016 at 10:58 AM, Paolo Bonzini wrote: > > > On 18/03/2016 18:42, David Matlack wrote: >> On Fri, Mar 18, 2016 at 9:09 AM, Paolo Bonzini wrote: >>> Patches 1 and 2 fix two cases where a guest could hang at 100% CPU >>> due to mis-emulation of a failing invept or invvpid. >> >>