From: Marc Zyngier <maz@kernel.org>
To: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] arm64: kvm: fix IDMAP overlap with HYP VA
Date: Sun, 19 Jan 2020 17:43:27 +0000 [thread overview]
Message-ID: <20200119174327.4b2c514e@why> (raw)
In-Reply-To: <E1ilAiY-0000MA-RG@rmk-PC.armlinux.org.uk>
On Sat, 28 Dec 2019 11:57:14 +0000
Russell King <rmk+kernel@armlinux.org.uk> wrote:
> Booting 5.4 on LX2160A reveals that KVM is non-functional:
>
> kvm: Limiting the IPA size due to kernel Virtual Address limit
> kvm [1]: IPA Size Limit: 43bits
> kvm [1]: IDMAP intersecting with HYP VA, unable to continue
> kvm [1]: error initializing Hyp mode: -22
>
> Debugging shows:
>
> kvm [1]: IDMAP page: 81a26000
> kvm [1]: HYP VA range: 0:22ffffffff
>
> as RAM is located at:
>
> 80000000-fbdfffff : System RAM
> 2080000000-237fffffff : System RAM
>
> Comparing this with the same kernel on Armada 8040 shows:
>
> kvm: Limiting the IPA size due to kernel Virtual Address limit
> kvm [1]: IPA Size Limit: 43bits
> kvm [1]: IDMAP page: 2a26000
> kvm [1]: HYP VA range: 4800000000:493fffffff
> ...
> kvm [1]: Hyp mode initialized successfully
>
> which indicates that hyp_va_msb is set, and is always set to the
> opposite value of the idmap page to avoid the overlap. This does not
> happen with the LX2160A.
>
> Further debugging shows vabits_actual = 39, kva_msb = 38 on LX2160A and
> kva_msb = 33 on Armada 8040. Looking at the bit layout of the HYP VA,
> there is still one bit available for hyp_va_msb. Set this bit
> appropriately. This allows kvm to be functional on the LX2160A, but
> without any HYP VA randomisation:
>
> kvm: Limiting the IPA size due to kernel Virtual Address limit
> kvm [1]: IPA Size Limit: 43bits
> kvm [1]: IDMAP page: 81a24000
> kvm [1]: HYP VA range: 4000000000:62ffffffff
> ...
> kvm [1]: Hyp mode initialized successfully
>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
I've applied this to kvmarm-next with a couple of cleanups, and
preserving the fallback when the tag is zero (only the mask gets
applied, without any ROR or ADD).
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: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] arm64: kvm: fix IDMAP overlap with HYP VA
Date: Sun, 19 Jan 2020 17:43:27 +0000 [thread overview]
Message-ID: <20200119174327.4b2c514e@why> (raw)
In-Reply-To: <E1ilAiY-0000MA-RG@rmk-PC.armlinux.org.uk>
On Sat, 28 Dec 2019 11:57:14 +0000
Russell King <rmk+kernel@armlinux.org.uk> wrote:
> Booting 5.4 on LX2160A reveals that KVM is non-functional:
>
> kvm: Limiting the IPA size due to kernel Virtual Address limit
> kvm [1]: IPA Size Limit: 43bits
> kvm [1]: IDMAP intersecting with HYP VA, unable to continue
> kvm [1]: error initializing Hyp mode: -22
>
> Debugging shows:
>
> kvm [1]: IDMAP page: 81a26000
> kvm [1]: HYP VA range: 0:22ffffffff
>
> as RAM is located at:
>
> 80000000-fbdfffff : System RAM
> 2080000000-237fffffff : System RAM
>
> Comparing this with the same kernel on Armada 8040 shows:
>
> kvm: Limiting the IPA size due to kernel Virtual Address limit
> kvm [1]: IPA Size Limit: 43bits
> kvm [1]: IDMAP page: 2a26000
> kvm [1]: HYP VA range: 4800000000:493fffffff
> ...
> kvm [1]: Hyp mode initialized successfully
>
> which indicates that hyp_va_msb is set, and is always set to the
> opposite value of the idmap page to avoid the overlap. This does not
> happen with the LX2160A.
>
> Further debugging shows vabits_actual = 39, kva_msb = 38 on LX2160A and
> kva_msb = 33 on Armada 8040. Looking at the bit layout of the HYP VA,
> there is still one bit available for hyp_va_msb. Set this bit
> appropriately. This allows kvm to be functional on the LX2160A, but
> without any HYP VA randomisation:
>
> kvm: Limiting the IPA size due to kernel Virtual Address limit
> kvm [1]: IPA Size Limit: 43bits
> kvm [1]: IDMAP page: 81a24000
> kvm [1]: HYP VA range: 4000000000:62ffffffff
> ...
> kvm [1]: Hyp mode initialized successfully
>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
I've applied this to kvmarm-next with a couple of cleanups, and
preserving the fallback when the tag is zero (only the mask gets
applied, without any ROR or ADD).
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
next prev parent reply other threads:[~2020-01-19 17:43 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-28 11:57 [PATCH v2] arm64: kvm: fix IDMAP overlap with HYP VA Russell King
2019-12-28 11:57 ` Russell King
2020-01-19 17:43 ` Marc Zyngier [this message]
2020-01-19 17:43 ` Marc Zyngier
2020-01-19 19:43 ` Russell King - ARM Linux admin
2020-01-19 19:43 ` Russell King - ARM Linux admin
2020-01-20 8:20 ` Marc Zyngier
2020-01-20 8:20 ` Marc Zyngier
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