Re: [PATCH RFC 0/5] KVM: x86: KVM_MEM_ALLONES memory

2020-05-15 Thread Peter Xu
On Thu, May 14, 2020 at 06:03:20PM -0700, Andy Lutomirski wrote: > On Thu, May 14, 2020 at 3:56 PM Sean Christopherson > wrote: > > > > On Thu, May 14, 2020 at 06:05:16PM -0400, Peter Xu wrote: > > > On Thu, May 14, 2020 at 08:05:35PM +0200, Vitaly Kuznetsov wrote: > > > > The idea of the patchset

Re: [PATCH RFC 0/5] KVM: x86: KVM_MEM_ALLONES memory

2020-05-15 Thread Vitaly Kuznetsov
Sean Christopherson writes: > On Thu, May 14, 2020 at 07:22:50PM -0400, Peter Xu wrote: >> On Thu, May 14, 2020 at 03:56:24PM -0700, Sean Christopherson wrote: >> > On Thu, May 14, 2020 at 06:05:16PM -0400, Peter Xu wrote: >> > > E.g., shm_open() with a handle and fill one 0xff page, then remap i

Re: [PATCH RFC 0/5] KVM: x86: KVM_MEM_ALLONES memory

2020-05-14 Thread Andy Lutomirski
On Thu, May 14, 2020 at 3:56 PM Sean Christopherson wrote: > > On Thu, May 14, 2020 at 06:05:16PM -0400, Peter Xu wrote: > > On Thu, May 14, 2020 at 08:05:35PM +0200, Vitaly Kuznetsov wrote: > > > The idea of the patchset was suggested by Michael S. Tsirkin. > > > > > > PCIe config space can (depe

Re: [PATCH RFC 0/5] KVM: x86: KVM_MEM_ALLONES memory

2020-05-14 Thread Sean Christopherson
On Thu, May 14, 2020 at 07:22:50PM -0400, Peter Xu wrote: > On Thu, May 14, 2020 at 03:56:24PM -0700, Sean Christopherson wrote: > > On Thu, May 14, 2020 at 06:05:16PM -0400, Peter Xu wrote: > > > E.g., shm_open() with a handle and fill one 0xff page, then remap it to > > > anywhere needed in QEMU?

Re: [PATCH RFC 0/5] KVM: x86: KVM_MEM_ALLONES memory

2020-05-14 Thread Peter Xu
On Thu, May 14, 2020 at 03:56:24PM -0700, Sean Christopherson wrote: > On Thu, May 14, 2020 at 06:05:16PM -0400, Peter Xu wrote: > > On Thu, May 14, 2020 at 08:05:35PM +0200, Vitaly Kuznetsov wrote: > > > The idea of the patchset was suggested by Michael S. Tsirkin. > > > > > > PCIe config space c

Re: [PATCH RFC 0/5] KVM: x86: KVM_MEM_ALLONES memory

2020-05-14 Thread Sean Christopherson
On Thu, May 14, 2020 at 06:05:16PM -0400, Peter Xu wrote: > On Thu, May 14, 2020 at 08:05:35PM +0200, Vitaly Kuznetsov wrote: > > The idea of the patchset was suggested by Michael S. Tsirkin. > > > > PCIe config space can (depending on the configuration) be quite big but > > usually is sparsely po

Re: [PATCH RFC 0/5] KVM: x86: KVM_MEM_ALLONES memory

2020-05-14 Thread Peter Xu
On Thu, May 14, 2020 at 08:05:35PM +0200, Vitaly Kuznetsov wrote: > The idea of the patchset was suggested by Michael S. Tsirkin. > > PCIe config space can (depending on the configuration) be quite big but > usually is sparsely populated. Guest may scan it by accessing individual > device's page w

[PATCH RFC 0/5] KVM: x86: KVM_MEM_ALLONES memory

2020-05-14 Thread Vitaly Kuznetsov
The idea of the patchset was suggested by Michael S. Tsirkin. PCIe config space can (depending on the configuration) be quite big but usually is sparsely populated. Guest may scan it by accessing individual device's page which, when device is missing, is supposed to have 'pci holes' semantics: rea