[AMD Public Use]
-----Original Message----- From: Sean Christopherson <sea...@google.com> Sent: Tuesday, February 16, 2021 7:03 PM To: Kalra, Ashish <ashish.ka...@amd.com> Cc: pbonz...@redhat.com; t...@linutronix.de; mi...@redhat.com; h...@zytor.com; rkrc...@redhat.com; j...@8bytes.org; b...@suse.de; Lendacky, Thomas <thomas.lenda...@amd.com>; x...@kernel.org; k...@vger.kernel.org; linux-kernel@vger.kernel.org; srutherf...@google.com; venu.busire...@oracle.com; Singh, Brijesh <brijesh.si...@amd.com> Subject: Re: [PATCH v10 10/16] KVM: x86: Introduce KVM_GET_SHARED_PAGES_LIST ioctl On Thu, Feb 04, 2021, Ashish Kalra wrote: > From: Brijesh Singh <brijesh.si...@amd.com> > > The ioctl is used to retrieve a guest's shared pages list. >What's the performance hit to boot time if KVM_HC_PAGE_ENC_STATUS is passed >through to userspace? That way, userspace could manage the set of pages >in >whatever data structure they want, and these get/set ioctls go away. I will be more concerned about performance hit during guest DMA I/O if the page encryption status hypercalls are passed through to user-space, a lot of guest DMA I/O dynamically sets up pages for encryption and then flips them at DMA completion, so guest I/O will surely take a performance hit with this pass-through stuff. Thanks, Ashish
