From: Paolo Bonzini <pbonzini@redhat.com>
To: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"peterz@infradead.org" <peterz@infradead.org>,
"keescook@chromium.org" <keescook@chromium.org>,
"Christopherson, Sean J" <sean.j.christopherson@intel.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"x86@kernel.org" <x86@kernel.org>,
"luto@kernel.org" <luto@kernel.org>,
"Hansen, Dave" <dave.hansen@intel.com>
Cc: "kristen@linux.intel.com" <kristen@linux.intel.com>,
"Dock, Deneen T" <deneen.t.dock@intel.com>,
"yu.c.zhang@linux.intel.com" <yu.c.zhang@linux.intel.com>
Subject: Re: [RFC PATCH 03/13] kvm: Add XO memslot type
Date: Sun, 6 Oct 2019 18:15:38 +0200 [thread overview]
Message-ID: <dc9ea270-489a-cd7c-fd68-26f22b5e49c6@redhat.com> (raw)
In-Reply-To: <9b885e65c3ec0ab8b4de0d38f2f20686a7afe0d0.camel@intel.com>
On 04/10/19 21:06, Edgecombe, Rick P wrote:
> The reasoning was that it seems like KVM leaves it to userspace to control the
> physical address space layout since userspace decides the supported physical
> address bits and lays out memory in the physical address space. So duplication
> with XO memslots was an attempt was to keep the logic around that together.
>
> I'll take another look at doing it this way though. I think userspace may still
> need to adjust the MAXPHYADDR and be aware it can't layout memory in the XO
> range.
Right, you would have to use KVM_ENABLE_CAP passing the desired X bit
(which must be < MAXPHYADDR) as the argument. Userspace needs to know
that it must then make MAXPHYADDR in the guest CPUID equal to the
argument. When the MSR is written to 1, bit "MAXPHYADDR-1" in the page
table entries becomes an XO bit.
Paolo
next prev parent reply other threads:[~2019-10-06 16:15 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-03 21:23 [RFC PATCH 00/13] XOM for KVM guest userspace Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 01/13] kvm: Enable MTRR to work with GFNs with perm bits Rick Edgecombe
2019-10-14 6:47 ` Yu Zhang
2019-10-14 18:44 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 02/13] kvm: Add support for X86_FEATURE_KVM_XO Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 03/13] kvm: Add XO memslot type Rick Edgecombe
2019-10-04 7:27 ` Paolo Bonzini
2019-10-04 19:06 ` Edgecombe, Rick P
2019-10-06 16:15 ` Paolo Bonzini [this message]
2019-10-03 21:23 ` [RFC PATCH 04/13] kvm, vmx: Add support for gva exit qualification Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 05/13] kvm: Add #PF injection for KVM XO Rick Edgecombe
2019-10-04 7:42 ` Paolo Bonzini
2019-10-04 19:11 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 06/13] kvm: Add KVM_CAP_EXECONLY_MEM Rick Edgecombe
2019-10-04 7:24 ` Paolo Bonzini
2019-10-04 19:11 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 07/13] kvm: Add docs for KVM_CAP_EXECONLY_MEM Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 08/13] x86/boot: Rename USE_EARLY_PGTABLE_L5 Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 09/13] x86/cpufeature: Add detection of KVM XO Rick Edgecombe
2019-10-29 23:33 ` Kees Cook
2019-10-29 23:52 ` Edgecombe, Rick P
2019-10-30 14:55 ` Sean Christopherson
2019-10-30 21:02 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 10/13] x86/mm: Add NR page bit for " Rick Edgecombe
2019-10-04 7:33 ` Paolo Bonzini
2019-10-03 21:23 ` [RFC PATCH 11/13] x86, ptdump: Add NR bit to page table dump Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 12/13] mmap: Add XO support for KVM XO Rick Edgecombe
2019-10-04 7:34 ` Paolo Bonzini
2019-10-04 19:12 ` Edgecombe, Rick P
2019-10-03 21:24 ` [RFC PATCH 13/13] x86/Kconfig: Add Kconfig for KVM based XO Rick Edgecombe
2019-10-29 23:36 ` Kees Cook
2019-10-30 0:01 ` Edgecombe, Rick P
2019-10-30 18:36 ` Kees Cook
2019-10-04 7:22 ` [RFC PATCH 00/13] XOM for KVM guest userspace Paolo Bonzini
2019-10-04 19:03 ` Edgecombe, Rick P
2019-10-04 14:56 ` Andy Lutomirski
2019-10-04 14:56 ` Andy Lutomirski
2019-10-04 20:09 ` Edgecombe, Rick P
2019-10-05 1:33 ` Andy Lutomirski
2019-10-05 1:33 ` Andy Lutomirski
2019-10-07 18:14 ` Edgecombe, Rick P
2019-10-29 23:40 ` Kees Cook
2019-10-30 0:27 ` Edgecombe, Rick P
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