|
Message-ID: <7c7f7ad7-d8ee-cf12-9ec6-1a1d20b2e653@infradead.org> Date: Thu, 19 Jul 2018 18:11:11 -0700 From: Randy Dunlap <rdunlap@...radead.org> To: Ahmed Abd El Mawgood <ahmedsoliman0x666@...il.com>, kvm@...r.kernel.org, Kernel Hardening <kernel-hardening@...ts.openwall.com>, virtualization@...ts.linux-foundation.org, linux-doc@...r.kernel.org, x86@...nel.org Cc: Paolo Bonzini <pbonzini@...hat.com>, rkrcmar@...hat.com, nathan Corbet <corbet@....net>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, hpa@...or.com, Kees Cook <keescook@...omium.org>, Ard Biesheuvel <ard.biesheuvel@...aro.org>, David Hildenbrand <david@...hat.com>, Boris Lukashev <blukashev@...pervictus.com>, David Vrabel <david.vrabel@...anix.com>, nigel.edwards@....com, Rik van Riel <riel@...riel.com> Subject: Re: [PATCH 1/3] [RFC V3] KVM: X86: Memory ROE documentation On 07/19/2018 02:38 PM, Ahmed Abd El Mawgood wrote: > Documentation/virtual/kvm/hypercalls.txt | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt > index a890529c63ed..a9db68adb7c9 100644 > --- a/Documentation/virtual/kvm/hypercalls.txt > +++ b/Documentation/virtual/kvm/hypercalls.txt > @@ -121,3 +121,17 @@ compute the CLOCK_REALTIME for its clock, at the same instant. > > Returns KVM_EOPNOTSUPP if the host does not use TSC clocksource, > or if clock type is different than KVM_CLOCK_PAIRING_WALLCLOCK. > + > +7. KVM_HC_HMROE > +---------------- > +Architecture: x86 > +Status: active > +Purpose: Hypercall used to apply Read-Only Enforcement to guest pages > +Usage: > + a0: start address of page that should be protected. Is this done one page per call? No grouping, no multiple pages? > + > +This hypercall lets a guest kernel to have part of its read/write memory lets a guest kernel have part of > +converted into read-only. This action is irreversible. KVM_HC_HMROE can > +not be triggered from guest Ring 3 (user mode). The reason is that user > +mode malicious software can make use of it enforce read only protection on make use of it to enforce > +an arbitrary memory page thus crashing the kernel. > -- ~Randy
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.