From: Marc Zyngier <marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu Cc: Shannon Zhao <shannon.zhao@linaro.org> Subject: [PATCH v2 7/9] arm64: KVM: Do not corrupt registers on failed 64bit CP read Date: Mon, 27 Mar 2017 17:03:43 +0100 [thread overview] Message-ID: <20170327160345.12402-8-marc.zyngier@arm.com> (raw) In-Reply-To: <20170327160345.12402-1-marc.zyngier@arm.com> If we fail to emulate a mrrc instruction, we: 1) deliver an exception, 2) spit a nastygram on the console, 3) write back some garbage to Rt/Rt2 While 1) and 2) are perfectly acceptable, 3) is out of the scope of the architecture... Let's mimick the code in kvm_handle_cp_32 and be more cautious. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm64/kvm/sys_regs.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 4e5d4eee8cec..1080a76e960f 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1678,20 +1678,18 @@ static int kvm_handle_cp_64(struct kvm_vcpu *vcpu, params.regval |= vcpu_get_reg(vcpu, Rt2) << 32; } - if (!emulate_cp(vcpu, ¶ms, target_specific, nr_specific)) - goto out; - if (!emulate_cp(vcpu, ¶ms, global, nr_global)) - goto out; - - unhandled_cp_access(vcpu, ¶ms); + if (!emulate_cp(vcpu, ¶ms, target_specific, nr_specific) || + !emulate_cp(vcpu, ¶ms, global, nr_global)) { + /* Split up the value between registers for the read side */ + if (!params.is_write) { + vcpu_set_reg(vcpu, Rt, lower_32_bits(params.regval)); + vcpu_set_reg(vcpu, Rt2, upper_32_bits(params.regval)); + } -out: - /* Split up the value between registers for the read side */ - if (!params.is_write) { - vcpu_set_reg(vcpu, Rt, lower_32_bits(params.regval)); - vcpu_set_reg(vcpu, Rt2, upper_32_bits(params.regval)); + return 1; } + unhandled_cp_access(vcpu, ¶ms); return 1; } -- 2.11.0
WARNING: multiple messages have this Message-ID (diff)
From: marc.zyngier@arm.com (Marc Zyngier) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 7/9] arm64: KVM: Do not corrupt registers on failed 64bit CP read Date: Mon, 27 Mar 2017 17:03:43 +0100 [thread overview] Message-ID: <20170327160345.12402-8-marc.zyngier@arm.com> (raw) In-Reply-To: <20170327160345.12402-1-marc.zyngier@arm.com> If we fail to emulate a mrrc instruction, we: 1) deliver an exception, 2) spit a nastygram on the console, 3) write back some garbage to Rt/Rt2 While 1) and 2) are perfectly acceptable, 3) is out of the scope of the architecture... Let's mimick the code in kvm_handle_cp_32 and be more cautious. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm64/kvm/sys_regs.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 4e5d4eee8cec..1080a76e960f 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1678,20 +1678,18 @@ static int kvm_handle_cp_64(struct kvm_vcpu *vcpu, params.regval |= vcpu_get_reg(vcpu, Rt2) << 32; } - if (!emulate_cp(vcpu, ¶ms, target_specific, nr_specific)) - goto out; - if (!emulate_cp(vcpu, ¶ms, global, nr_global)) - goto out; - - unhandled_cp_access(vcpu, ¶ms); + if (!emulate_cp(vcpu, ¶ms, target_specific, nr_specific) || + !emulate_cp(vcpu, ¶ms, global, nr_global)) { + /* Split up the value between registers for the read side */ + if (!params.is_write) { + vcpu_set_reg(vcpu, Rt, lower_32_bits(params.regval)); + vcpu_set_reg(vcpu, Rt2, upper_32_bits(params.regval)); + } -out: - /* Split up the value between registers for the read side */ - if (!params.is_write) { - vcpu_set_reg(vcpu, Rt, lower_32_bits(params.regval)); - vcpu_set_reg(vcpu, Rt2, upper_32_bits(params.regval)); + return 1; } + unhandled_cp_access(vcpu, ¶ms); return 1; } -- 2.11.0
next prev parent reply other threads:[~2017-03-27 16:03 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-03-27 16:03 [PATCH v2 0/9] arm64: KVM: Fix PMU exception generation Marc Zyngier 2017-03-27 16:03 ` Marc Zyngier 2017-03-27 16:03 ` [PATCH v2 1/9] arm64: KVM: PMU: Refactor pmu_*_el0_disabled Marc Zyngier 2017-03-27 16:03 ` Marc Zyngier 2017-03-27 17:03 ` Suzuki K Poulose 2017-03-27 17:03 ` Suzuki K Poulose 2017-03-27 17:11 ` Marc Zyngier 2017-03-27 17:11 ` Marc Zyngier 2017-03-28 12:46 ` Christoffer Dall 2017-03-28 12:46 ` Christoffer Dall 2017-03-28 13:21 ` Marc Zyngier 2017-03-28 13:21 ` Marc Zyngier 2017-03-27 16:03 ` [PATCH v2 2/9] arm64: KVM: PMU: Inject UNDEF exception on illegal register access Marc Zyngier 2017-03-27 16:03 ` Marc Zyngier 2017-03-28 12:44 ` Christoffer Dall 2017-03-28 12:44 ` Christoffer Dall 2017-03-27 16:03 ` [PATCH v2 3/9] arm64: KVM: PMU: Inject UNDEF on non-privileged accesses Marc Zyngier 2017-03-27 16:03 ` Marc Zyngier 2017-03-28 12:45 ` Christoffer Dall 2017-03-28 12:45 ` Christoffer Dall 2017-03-27 16:03 ` [PATCH v2 4/9] arm64: KVM: Make unexpected reads from WO registers inject an undef Marc Zyngier 2017-03-27 16:03 ` Marc Zyngier 2017-03-28 12:45 ` Christoffer Dall 2017-03-28 12:45 ` Christoffer Dall 2017-03-27 16:03 ` [PATCH v2 5/9] arm64: KVM: PMU: Inject UNDEF on read access to PMSWINC_EL0 Marc Zyngier 2017-03-27 16:03 ` Marc Zyngier 2017-03-28 12:45 ` Christoffer Dall 2017-03-28 12:45 ` Christoffer Dall 2017-03-27 16:03 ` [PATCH v2 6/9] arm64: KVM: Treat sysreg accessors returning false as successful Marc Zyngier 2017-03-27 16:03 ` Marc Zyngier 2017-03-28 12:45 ` Christoffer Dall 2017-03-28 12:45 ` Christoffer Dall 2017-03-27 16:03 ` Marc Zyngier [this message] 2017-03-27 16:03 ` [PATCH v2 7/9] arm64: KVM: Do not corrupt registers on failed 64bit CP read Marc Zyngier 2017-03-28 12:46 ` Christoffer Dall 2017-03-28 12:46 ` Christoffer Dall 2017-03-28 13:24 ` Marc Zyngier 2017-03-28 13:24 ` Marc Zyngier 2017-03-27 16:03 ` [PATCH v2 8/9] arm: KVM: Make unexpected register accesses inject an undef Marc Zyngier 2017-03-27 16:03 ` Marc Zyngier 2017-03-28 12:46 ` Christoffer Dall 2017-03-28 12:46 ` Christoffer Dall 2017-03-27 16:03 ` [PATCH v2 9/9] arm: KVM: Treat CP15 accessors returning false as successful Marc Zyngier 2017-03-27 16:03 ` Marc Zyngier 2017-03-28 12:46 ` Christoffer Dall 2017-03-28 12:46 ` Christoffer Dall 2017-03-28 13:37 ` [PATCH v2 0/9] arm64: KVM: Fix PMU exception generation Christoffer Dall 2017-03-28 13:37 ` Christoffer Dall
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