[V5,1/5] KVM: X86: Memory ROE documentation
diff mbox series

Message ID 20181026151223.16810-2-ahmedsoliman0x666@gmail.com
State New
Headers show
Series
  • KVM: X86: Introducing ROE Protection Kernel Hardening
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Commit Message

Ahmed Soliman Oct. 26, 2018, 3:12 p.m. UTC
Following up with my previous threads on KVM assisted Anti rootkit
protections.
The current version doesn't address the attacks involving pages
remapping. It is still design in progress, nevertheless, it will be in
my later patch sets.

Signed-off-by: Ahmed Abd El Mawgood <ahmedsoliman0x666@gmail.com>
---
 Documentation/virtual/kvm/hypercalls.txt | 31 ++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

Comments

Sean Christopherson Oct. 29, 2018, 4:42 p.m. UTC | #1
On Fri, Oct 26, 2018 at 05:12:19PM +0200, Ahmed Abd El Mawgood wrote:
> Following up with my previous threads on KVM assisted Anti rootkit
> protections.

All of the changelogs in this series need to be rewritten to adhere to
Documentation/process[1].  In particular, use imperative mood and
describe why/what is being done in a self-contained manner, e.g. the
above line isn't very helpful without a lot of prior context.

[1] https://github.com/torvalds/linux/blob/master/Documentation/process/submitting-patches.rst#2-describe-your-changes

> The current version doesn't address the attacks involving pages
> remapping. It is still design in progress, nevertheless, it will be in
> my later patch sets.

This series should be tagged RFC if its design is a WIP.
Ahmed Soliman Oct. 31, 2018, 4:02 p.m. UTC | #2
On Mon, 29 Oct 2018 at 18:42, Sean Christopherson
<sean.j.christopherson@intel.com> wrote:
>
> On Fri, Oct 26, 2018 at 05:12:19PM +0200, Ahmed Abd El Mawgood wrote:
> > Following up with my previous threads on KVM assisted Anti rootkit
> > protections.
>
> All of the changelogs in this series need to be rewritten to adhere to
> Documentation/process[1].  In particular, use imperative mood and
> describe why/what is being done in a self-contained manner, e.g. the
> above line isn't very helpful without a lot of prior context.
>
> [1] https://github.com/torvalds/linux/blob/master/Documentation/process/submitting-patches.rst#2-describe-your-changes
>
> > The current version doesn't address the attacks involving pages
> > remapping. It is still design in progress, nevertheless, it will be in
> > my later patch sets.
>
> This series should be tagged RFC if its design is a WIP.
Ops my bad, the current description is obsolete and I forgot to remove
it. I will have this fixed as well as your other comments in the next
patch series.

Patch
diff mbox series

diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt
index da24c138c8d1..8af64d826f03 100644
--- a/Documentation/virtual/kvm/hypercalls.txt
+++ b/Documentation/virtual/kvm/hypercalls.txt
@@ -141,3 +141,34 @@  a0 corresponds to the APIC ID in the third argument (a2), bit 1
 corresponds to the APIC ID a2+1, and so on.
 
 Returns the number of CPUs to which the IPIs were delivered successfully.
+
+7. KVM_HC_ROE
+----------------
+Architecture: x86
+Status: active
+Purpose: Hypercall used to apply Read-Only Enforcement to guest memory and
+registers
+Usage 1:
+     a0: ROE_VERSION
+
+Returns non-signed number that represents the current version of ROE
+implementation current version.
+
+Usage 2:
+
+     a0: ROE_MPROTECT	(requires version >= 1)
+     a1: Start address aligned to page boundary.
+     a2: Number of pages to be protected.
+
+This configuration lets a guest kernel have part of its read/write memory
+converted into read-only.  This action is irreversible.
+Upon successful run, the number of pages protected is returned.
+
+Error codes:
+	-KVM_ENOSYS: system call being triggered from ring 3 or it is not
+	implemented.
+	-EINVAL: error based on given parameters.
+
+Notes: KVM_HC_ROE can not be triggered from guest Ring 3 (user mode). The
+reason is that user mode malicious software can make use of it to enforce read
+only protection on an arbitrary memory page thus crashing the kernel.