| Message ID | 1539773280-4159-7-git-send-email-amit.kachhap@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add ARMv8.3 pointer authentication for kvm guest | expand |
On Wed, Oct 17, 2018 at 04:17:59PM +0530, Amit Daniel Kachhap wrote: > The documentation is updated to help in using pointer authentication > for KVM guests. > > Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Christoffer Dall <christoffer.dall@arm.com> > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: kvmarm@lists.cs.columbia.edu > --- > Documentation/arm64/pointer-authentication.txt | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/Documentation/arm64/pointer-authentication.txt b/Documentation/arm64/pointer-authentication.txt > index 8a9cb57..b00d735 100644 > --- a/Documentation/arm64/pointer-authentication.txt > +++ b/Documentation/arm64/pointer-authentication.txt > @@ -78,7 +78,13 @@ to TTBR1 addresses (e.g. kernel pointers). > Virtualization > -------------- > > -Pointer authentication is not currently supported in KVM guests. KVM > +Pointer authentication is enabled in KVM guest when virtual machine is > +created by passing a flag requesting this feature to be enabled. Without > +this flag, pointer authentication is not enabled in KVM guests and KVM > will mask the feature bits from ID_AA64ISAR1_EL1, and attempted use of > the feature will result in an UNDEFINED exception being injected into > the guest. > + > +The flag to enable this feature is KVM_ARM_VCPU_PTRAUTH and should be > +used in KVM API KVM_ARM_VCPU_INIT. The pointer authentication key > +registers are hidden from userspace if this feature is not enabled. > -- > 2.7.4 > I think this is placed in the wrong file. Any information about the KVM API should go in Documentation/virtual/kvm/api.txt. The only information about KVM that belongs in this file would be host running a VM with ptrauth can affect the host's ptrauth state (if that applies). Thanks, Christoffer
diff --git a/Documentation/arm64/pointer-authentication.txt b/Documentation/arm64/pointer-authentication.txt index 8a9cb57..b00d735 100644 --- a/Documentation/arm64/pointer-authentication.txt +++ b/Documentation/arm64/pointer-authentication.txt @@ -78,7 +78,13 @@ to TTBR1 addresses (e.g. kernel pointers). Virtualization -------------- -Pointer authentication is not currently supported in KVM guests. KVM +Pointer authentication is enabled in KVM guest when virtual machine is +created by passing a flag requesting this feature to be enabled. Without +this flag, pointer authentication is not enabled in KVM guests and KVM will mask the feature bits from ID_AA64ISAR1_EL1, and attempted use of the feature will result in an UNDEFINED exception being injected into the guest. + +The flag to enable this feature is KVM_ARM_VCPU_PTRAUTH and should be +used in KVM API KVM_ARM_VCPU_INIT. The pointer authentication key +registers are hidden from userspace if this feature is not enabled.
The documentation is updated to help in using pointer authentication for KVM guests. Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: kvmarm@lists.cs.columbia.edu --- Documentation/arm64/pointer-authentication.txt | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)