From: Marc Zyngier <maz@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Elliot Berman <quic_eberman@quicinc.com>,
linux-kernel@vger.kernel.org, Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] KVM: arm64: Report Protected KVM cap only if KVM is enabled
Date: Fri, 09 Sep 2022 13:47:34 +0100 [thread overview]
Message-ID: <485617e0d3635c1961ab30c1ad930c81@kernel.org> (raw)
In-Reply-To: <Yxs1H3+iI8Y7+Zbu@arm.com>
On 2022-09-09 13:44, Catalin Marinas wrote:
> On Thu, Sep 01, 2022 at 09:01:22PM -0700, Elliot Berman wrote:
>> If "kvm-arm.mode=protected" is present on kernel command line, but the
>> kernel doesn't actually support KVM because it booted from EL1, the
>> ARM64_KVM_PROTECTED_MODE capability is misleadingly reported as
>> present.
>> Fix this by adding a check whether we booted from EL2.
>>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: David Brazdil <dbrazdil@google.com>
>> Cc: Marc Zyngier <maz@kernel.org>
>> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
>> ---
>> arch/arm64/kernel/cpufeature.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/kernel/cpufeature.c
>> b/arch/arm64/kernel/cpufeature.c
>> index 8d88433de81d..866667be0651 100644
>> --- a/arch/arm64/kernel/cpufeature.c
>> +++ b/arch/arm64/kernel/cpufeature.c
>> @@ -1974,7 +1974,7 @@ static void cpu_enable_mte(struct
>> arm64_cpu_capabilities const *cap)
>> #ifdef CONFIG_KVM
>> static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities
>> *entry, int __unused)
>> {
>> - return kvm_get_mode() == KVM_MODE_PROTECTED;
>> + return is_hyp_mode_available() && kvm_get_mode() ==
>> KVM_MODE_PROTECTED;
>> }
>> #endif /* CONFIG_KVM */
>
> Could we not fix this in early_kvm_mode_cfg()?
That's be indeed preferable.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Elliot Berman <quic_eberman@quicinc.com>,
Will Deacon <will@kernel.org>, James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
David Brazdil <dbrazdil@google.com>
Subject: Re: [PATCH] KVM: arm64: Report Protected KVM cap only if KVM is enabled
Date: Fri, 09 Sep 2022 13:47:34 +0100 [thread overview]
Message-ID: <485617e0d3635c1961ab30c1ad930c81@kernel.org> (raw)
In-Reply-To: <Yxs1H3+iI8Y7+Zbu@arm.com>
On 2022-09-09 13:44, Catalin Marinas wrote:
> On Thu, Sep 01, 2022 at 09:01:22PM -0700, Elliot Berman wrote:
>> If "kvm-arm.mode=protected" is present on kernel command line, but the
>> kernel doesn't actually support KVM because it booted from EL1, the
>> ARM64_KVM_PROTECTED_MODE capability is misleadingly reported as
>> present.
>> Fix this by adding a check whether we booted from EL2.
>>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: David Brazdil <dbrazdil@google.com>
>> Cc: Marc Zyngier <maz@kernel.org>
>> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
>> ---
>> arch/arm64/kernel/cpufeature.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/kernel/cpufeature.c
>> b/arch/arm64/kernel/cpufeature.c
>> index 8d88433de81d..866667be0651 100644
>> --- a/arch/arm64/kernel/cpufeature.c
>> +++ b/arch/arm64/kernel/cpufeature.c
>> @@ -1974,7 +1974,7 @@ static void cpu_enable_mte(struct
>> arm64_cpu_capabilities const *cap)
>> #ifdef CONFIG_KVM
>> static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities
>> *entry, int __unused)
>> {
>> - return kvm_get_mode() == KVM_MODE_PROTECTED;
>> + return is_hyp_mode_available() && kvm_get_mode() ==
>> KVM_MODE_PROTECTED;
>> }
>> #endif /* CONFIG_KVM */
>
> Could we not fix this in early_kvm_mode_cfg()?
That's be indeed preferable.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Elliot Berman <quic_eberman@quicinc.com>,
Will Deacon <will@kernel.org>, James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
David Brazdil <dbrazdil@google.com>
Subject: Re: [PATCH] KVM: arm64: Report Protected KVM cap only if KVM is enabled
Date: Fri, 09 Sep 2022 13:47:34 +0100 [thread overview]
Message-ID: <485617e0d3635c1961ab30c1ad930c81@kernel.org> (raw)
In-Reply-To: <Yxs1H3+iI8Y7+Zbu@arm.com>
On 2022-09-09 13:44, Catalin Marinas wrote:
> On Thu, Sep 01, 2022 at 09:01:22PM -0700, Elliot Berman wrote:
>> If "kvm-arm.mode=protected" is present on kernel command line, but the
>> kernel doesn't actually support KVM because it booted from EL1, the
>> ARM64_KVM_PROTECTED_MODE capability is misleadingly reported as
>> present.
>> Fix this by adding a check whether we booted from EL2.
>>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: David Brazdil <dbrazdil@google.com>
>> Cc: Marc Zyngier <maz@kernel.org>
>> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
>> ---
>> arch/arm64/kernel/cpufeature.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/kernel/cpufeature.c
>> b/arch/arm64/kernel/cpufeature.c
>> index 8d88433de81d..866667be0651 100644
>> --- a/arch/arm64/kernel/cpufeature.c
>> +++ b/arch/arm64/kernel/cpufeature.c
>> @@ -1974,7 +1974,7 @@ static void cpu_enable_mte(struct
>> arm64_cpu_capabilities const *cap)
>> #ifdef CONFIG_KVM
>> static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities
>> *entry, int __unused)
>> {
>> - return kvm_get_mode() == KVM_MODE_PROTECTED;
>> + return is_hyp_mode_available() && kvm_get_mode() ==
>> KVM_MODE_PROTECTED;
>> }
>> #endif /* CONFIG_KVM */
>
> Could we not fix this in early_kvm_mode_cfg()?
That's be indeed preferable.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2022-09-09 12:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-02 4:01 [PATCH] KVM: arm64: Report Protected KVM cap only if KVM is enabled Elliot Berman
2022-09-02 4:01 ` Elliot Berman
2022-09-02 4:01 ` Elliot Berman
2022-09-09 12:44 ` Catalin Marinas
2022-09-09 12:44 ` Catalin Marinas
2022-09-09 12:44 ` Catalin Marinas
2022-09-09 12:47 ` Marc Zyngier [this message]
2022-09-09 12:47 ` Marc Zyngier
2022-09-09 12:47 ` Marc Zyngier
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