On 2020-02-18 17:43, James Morse wrote:
Hi Marc,
On 16/02/2020 18:53, Marc Zyngier wrote:
Our PMU code is only implementing the ARMv8.1 features, so let's
stick to this when reporting the feature set to the guest.
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 682fedd7700f..06b2d0dc6c73 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1093,6 +1093,11 @@ static u64 read_id_reg(const struct kvm_vcpu
*vcpu,
FEATURE(ID_AA64ISAR1_GPA) |
FEATURE(ID_AA64ISAR1_GPI));
break;
+ case SYS_ID_AA64DFR0_EL1:
+ /* Limit PMU to ARMv8.1 */
Not just limit, but upgrade too! (force?)
This looks safe because ARMV8_PMU_EVTYPE_EVENT always includes the
extra bits this added, and the register is always trapped.
That's definitely not what I intended! Let me fix that one.
The PMU version is also readable via ID_DFR0_EL1.PerfMon, should that
be sanitised to be the same? (I don't think we've hidden an aarch64
feature that also existed in aarch32 before).
Indeed, yet another oversight. I'll fix that too.
Regardless:
Reviewed-by: James Morse <james.morse@xxxxxxx>
You're way too kind! ;-)
M.
--
Jazz is not dead. It just smells funny...
