From: Andre Przywara <andre.przywara@arm.com>
To: Marc Zyngier <maz@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
Will Deacon <will@kernel.org>,
Alexandru Elisei <alexandru.elisei@arm.com>
Subject: Re: [PATCH 2/3] kvmtool: arm64: Use the maximum supported IPA size when creating the VM
Date: Thu, 18 Mar 2021 10:21:25 +0000 [thread overview]
Message-ID: <20210318102125.68de47db@slackpad.fritz.box> (raw)
In-Reply-To: <20210309163909.822149-3-maz@kernel.org>
On Tue, 9 Mar 2021 16:39:08 +0000
Marc Zyngier <maz@kernel.org> wrote:
Hi,
> Instead of just asking the the default VM size, request the maximum
> IPA size to the kernel, and use this at VM creation time.
>
> The IPA space is parametrized accordingly.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arm/aarch64/include/kvm/kvm-arch.h | 19 ++++++++++++++++---
> arm/aarch64/kvm.c | 15 +++++++++++++++
> 2 files changed, 31 insertions(+), 3 deletions(-)
>
> diff --git a/arm/aarch64/include/kvm/kvm-arch.h b/arm/aarch64/include/kvm/kvm-arch.h
> index 55ef8ed..159567b 100644
> --- a/arm/aarch64/include/kvm/kvm-arch.h
> +++ b/arm/aarch64/include/kvm/kvm-arch.h
> @@ -3,10 +3,23 @@
>
> struct kvm;
> unsigned long long kvm__arch_get_kern_offset(struct kvm *kvm, int fd);
> +int kvm__arch_get_ipa_limit(struct kvm *kvm);
>
> -#define ARM_MAX_MEMORY(kvm) ((kvm)->cfg.arch.aarch32_guest ? \
> - ARM_LOMAP_MAX_MEMORY : \
> - ARM_HIMAP_MAX_MEMORY)
> +#define ARM_MAX_MEMORY(kvm) ({ \
> + u64 max_ram; \
> + \
> + if ((kvm)->cfg.arch.aarch32_guest) { \
> + max_ram = ARM_LOMAP_MAX_MEMORY; \
> + } else { \
> + int ipabits = kvm__arch_get_ipa_limit(kvm); \
> + if (ipabits <= 0) \
> + max_ram = ARM_HIMAP_MAX_MEMORY; \
> + else \
> + max_ram = (1ULL << ipabits) - ARM_MEMORY_AREA; \
> + } \
> + \
> + max_ram; \
> +})
>
> #include "arm-common/kvm-arch.h"
>
> diff --git a/arm/aarch64/kvm.c b/arm/aarch64/kvm.c
> index 49e1dd3..c4f81d0 100644
> --- a/arm/aarch64/kvm.c
> +++ b/arm/aarch64/kvm.c
> @@ -46,3 +46,18 @@ fail:
> return 0x80000;
> }
>
> +int kvm__arch_get_ipa_limit(struct kvm *kvm)
> +{
> + int ret;
> +
> + ret = ioctl(kvm->sys_fd, KVM_CHECK_EXTENSION, KVM_CAP_ARM_VM_IPA_SIZE);
> + if (ret <= 0)
> + ret = 0;
> +
> + return ret;
> +}
> +
> +int kvm__get_vm_type(struct kvm *kvm)
> +{
> + return kvm__arch_get_ipa_limit(kvm);
Shouldn't that be funnelled through KVM_VM_TYPE_ARM_IPA_SIZE()?
Granted, that doesn't really do anything, but if I understand the
api.rst directly, it's logically needed to convert the IPA size into a
VM type.
Other than that looks good.
Cheers,
Andre
> +}
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next prev parent reply other threads:[~2021-03-18 10:23 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-09 16:39 [PATCH 0/3] kvmtool: Limit IPA space to what is actually required Marc Zyngier
2021-03-09 16:39 ` [PATCH 1/3] kvmtool: Abstract KVM_VM_TYPE into a weak function Marc Zyngier
2021-03-18 10:20 ` Andre Przywara
2021-03-09 16:39 ` [PATCH 2/3] kvmtool: arm64: Use the maximum supported IPA size when creating the VM Marc Zyngier
2021-03-18 10:21 ` Andre Przywara [this message]
2021-03-18 14:06 ` Marc Zyngier
2021-03-09 16:39 ` [PATCH 3/3][Do not merge] kvmtool: arm64: Configure VM with the minimal required IPA space Marc Zyngier
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