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authorMarc Zyngier <marc.zyngier@arm.com>2017-03-27 17:03:41 +0100
committerChristoffer Dall <cdall@linaro.org>2017-04-09 07:49:14 -0700
commite04432301607a6750e31d7db4cc4dfdd742ee7f8 (patch)
tree1ead31012b0df480add2bed9be469dade53b1df2 /arch
parentarm64: KVM: Make unexpected reads from WO registers inject an undef (diff)
downloadlinux-dev-e04432301607a6750e31d7db4cc4dfdd742ee7f8.tar.xz
linux-dev-e04432301607a6750e31d7db4cc4dfdd742ee7f8.zip
arm64: KVM: PMU: Inject UNDEF on read access to PMSWINC_EL0
PMSWINC_EL0 is a WO register, so let's UNDEF when reading from it (in the highly hypothetical case where this doesn't UNDEF at EL1). Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to '')
-rw-r--r--arch/arm64/kvm/sys_regs.c13
1 files changed, 6 insertions, 7 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 20f90c01af33..3fef01d75164 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -772,16 +772,15 @@ static bool access_pmswinc(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
+ if (!p->is_write)
+ return read_from_write_only(vcpu, p);
+
if (pmu_write_swinc_el0_disabled(vcpu))
return false;
- if (p->is_write) {
- mask = kvm_pmu_valid_counter_mask(vcpu);
- kvm_pmu_software_increment(vcpu, p->regval & mask);
- return true;
- }
-
- return false;
+ mask = kvm_pmu_valid_counter_mask(vcpu);
+ kvm_pmu_software_increment(vcpu, p->regval & mask);
+ return true;
}
static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,