From: Mark Rutland <mark.rutland@arm.com>
To: Kalesh Singh <kaleshsingh@google.com>
Cc: will@kernel.org, maz@kernel.org, qperret@google.com,
tabba@google.com, surenb@google.com, kernel-team@android.com,
Catalin Marinas <catalin.marinas@arm.com>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
Pasha Tatashin <pasha.tatashin@soleen.com>,
Joey Gouly <joey.gouly@arm.com>,
Peter Collingbourne <pcc@google.com>,
Andrew Scull <ascull@google.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH v2 4/9] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
Date: Tue, 22 Feb 2022 18:55:00 +0000 [thread overview]
Message-ID: <YhUxhEHNKlqip51u@lakrids> (raw)
In-Reply-To: <20220222165212.2005066-5-kaleshsingh@google.com>
On Tue, Feb 22, 2022 at 08:51:05AM -0800, Kalesh Singh wrote:
> Maps the stack pages in the flexible private VA range and allocates
> guard pages below the stack as unbacked VA space. The stack is aligned
> to twice its size to aid overflow detection (implemented in a subsequent
> patch in the series).
>
> Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
> ---
> arch/arm64/kvm/hyp/nvhe/setup.c | 25 +++++++++++++++++++++----
> 1 file changed, 21 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
> index 27af337f9fea..69df21320b09 100644
> --- a/arch/arm64/kvm/hyp/nvhe/setup.c
> +++ b/arch/arm64/kvm/hyp/nvhe/setup.c
> @@ -105,11 +105,28 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
> if (ret)
> return ret;
>
> - end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va;
> + /*
> + * Private mappings are allocated upwards from __io_map_base
> + * so allocate the guard page first then the stack.
> + */
> + start = (void *)pkvm_alloc_private_va_range(PAGE_SIZE, PAGE_SIZE);
> + if (IS_ERR_OR_NULL(start))
> + return PTR_ERR(start);
As on a prior patch, this usage of PTR_ERR() pattern is wrong when the
ptr is NULL.
> + /*
> + * The stack is aligned to twice its size to facilitate overflow
> + * detection.
> + */
> + end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_pa;
> start = end - PAGE_SIZE;
> - ret = pkvm_create_mappings(start, end, PAGE_HYP);
> - if (ret)
> - return ret;
> + start = (void *)__pkvm_create_private_mapping((phys_addr_t)start,
> + PAGE_SIZE, PAGE_SIZE * 2, PAGE_HYP);
> + if (IS_ERR_OR_NULL(start))
> + return PTR_ERR(start);
Likewise.
Thanks,
Mark.
> + end = start + PAGE_SIZE;
> +
> + /* Update stack_hyp_va to end of the stack's private VA range */
> + per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va = (unsigned long) end;
> }
>
> /*
> --
> 2.35.1.473.g83b2b277ed-goog
>
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next prev parent reply other threads:[~2022-02-22 18:56 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-22 16:51 [PATCH v2 0/9] KVM: arm64: Hypervisor stack enhancements Kalesh Singh
2022-02-22 16:51 ` [PATCH v2 1/9] KVM: arm64: Introduce hyp_alloc_private_va_range() Kalesh Singh
2022-02-22 18:53 ` Mark Rutland
2022-02-22 16:51 ` [PATCH v2 2/9] KVM: arm64: Introduce pkvm_alloc_private_va_range() Kalesh Singh
2022-02-22 16:51 ` [PATCH v2 3/9] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack Kalesh Singh
2022-02-22 16:51 ` [PATCH v2 4/9] KVM: arm64: Add guard pages for pKVM (protected nVHE) " Kalesh Singh
2022-02-22 18:55 ` Mark Rutland [this message]
2022-02-22 20:30 ` Kalesh Singh
2022-02-22 16:51 ` [PATCH v2 5/9] arm64: asm: Introduce test_sp_overflow macro Kalesh Singh
2022-02-22 18:32 ` Mark Rutland
2022-02-22 20:20 ` Kalesh Singh
2022-02-22 16:51 ` [PATCH v2 6/9] KVM: arm64: Detect and handle hypervisor stack overflows Kalesh Singh
2022-02-23 2:04 ` kernel test robot
2022-02-23 9:05 ` kernel test robot
2022-02-23 9:16 ` Marc Zyngier
2022-02-23 12:34 ` [kbuild-all] " Philip Li
2022-02-23 12:54 ` Marc Zyngier
2022-02-23 12:56 ` Ard Biesheuvel
2022-02-24 10:39 ` Marc Zyngier
2022-02-25 2:12 ` Chen, Rong A
2022-02-25 3:11 ` Kalesh Singh
2022-02-25 15:31 ` Marc Zyngier
2022-02-25 15:38 ` Ard Biesheuvel
2022-02-22 16:51 ` [PATCH v2 7/9] KVM: arm64: Add hypervisor overflow stack Kalesh Singh
2022-02-22 16:51 ` [PATCH v2 8/9] KVM: arm64: Unwind and dump nVHE HYP stacktrace Kalesh Singh
2022-02-22 16:51 ` [PATCH v2 9/9] KVM: arm64: Symbolize the nVHE HYP backtrace Kalesh Singh
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