[PATCH v3 6/7] arm64: docs: document KVM support of pointer authentication
From: Amit Daniel Kachhap <hidden>
Date: 2018-10-17 10:49:21
Also in:
kvmarm, lkml
Subsystem:
documentation, the rest · Maintainers:
Jonathan Corbet, Linus Torvalds
The documentation is updated to help in using pointer authentication for KVM guests. Signed-off-by: Amit Daniel Kachhap <redacted> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Christoffer Dall <redacted> Cc: Marc Zyngier <redacted> Cc: kvmarm at 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.
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2.7.4