From: Marc Zyngier <maz@kernel.org>
To: David Brazdil <dbrazdil@google.com>
Cc: kvm@vger.kernel.org, Suzuki K Poulose <suzuki.poulose@arm.com>,
kernel-team@android.com, James Morse <james.morse@arm.com>,
linux-arm-kernel@lists.infradead.org,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: Re: [PATCH 2/2] KVM: arm64: Advertise ID_AA64PFR0_EL1.CSV3=1 if the CPUs are Meltdown-safe
Date: Mon, 30 Nov 2020 15:40:16 +0000 [thread overview]
Message-ID: <4a398347b173c5c1a7a0ebd4b54a64bd@kernel.org> (raw)
In-Reply-To: <20201130152655.oyzs2l4qg2pfzxmv@google.com>
Hi David,
On 2020-11-30 15:26, David Brazdil wrote:
>> @@ -1227,9 +1229,16 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu
>> *vcpu,
>> (csv2 && arm64_get_spectre_v2_state() != SPECTRE_UNAFFECTED))
>> return -EINVAL;
>>
>> - /* We can only differ with CSV2, and anything else is an error */
>> + /* Same thing for CSV3 */
>> + csv3 = cpuid_feature_extract_unsigned_field(val,
>> ID_AA64PFR0_CSV3_SHIFT);
>> + if (csv3 > 1 ||
>> + (csv3 && arm64_get_meltdown_state() != SPECTRE_UNAFFECTED))
>> + return -EINVAL;
>> +
>> + /* We can only differ with CSV[23], and anything else is an error */
>> val ^= read_id_reg(vcpu, rd, false);
>> - val &= ~(0xFUL << ID_AA64PFR0_CSV2_SHIFT);
>> + val &= ~((0xFUL << ID_AA64PFR0_CSV2_SHIFT) ||
>> + (0xFUL << ID_AA64PFR0_CSV3_SHIFT));
>
> That boolean OR looks like a typo.
It definitely is. Who the hell is writing this code?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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prev parent reply other threads:[~2020-11-30 15:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-28 12:46 [PATCH 0/2] KVM: arm64: Expose CSV3 to guests on running on Meltdown-safe HW Marc Zyngier
2020-11-28 12:46 ` [PATCH 1/2] arm64: Make the Meltdown mitigation state available Marc Zyngier
2020-11-28 12:46 ` [PATCH 2/2] KVM: arm64: Advertise ID_AA64PFR0_EL1.CSV3=1 if the CPUs are Meltdown-safe Marc Zyngier
2020-11-30 15:26 ` David Brazdil
2020-11-30 15:40 ` Marc Zyngier [this message]
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