From: Catalin Marinas <catalin.marinas@arm.com>
To: Steven Price <steven.price@arm.com>
Cc: Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Dave Martin <Dave.Martin@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
qemu-devel@nongnu.org, Juan Quintela <quintela@redhat.com>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Richard Henderson <richard.henderson@linaro.org>,
Peter Maydell <peter.maydell@linaro.org>,
Haibo Xu <Haibo.Xu@arm.com>, Andrew Jones <drjones@redhat.com>
Subject: Re: [PATCH v4 2/2] arm64: kvm: Introduce MTE VCPU feature
Date: Tue, 17 Nov 2020 16:07:48 +0000 [thread overview]
Message-ID: <X7P1VLZhBh045tsr@trantor> (raw)
In-Reply-To: <20201026155727.36685-3-steven.price@arm.com>
Hi Steven,
On Mon, Oct 26, 2020 at 03:57:27PM +0000, Steven Price wrote:
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index 19aacc7d64de..38fe25310ca1 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -862,6 +862,26 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
> if (vma_pagesize == PAGE_SIZE && !force_pte)
> vma_pagesize = transparent_hugepage_adjust(memslot, hva,
> &pfn, &fault_ipa);
> +
> + /*
> + * The otherwise redundant test for system_supports_mte() allows the
> + * code to be compiled out when CONFIG_ARM64_MTE is not present.
> + */
> + if (system_supports_mte() && kvm->arch.mte_enabled && pfn_valid(pfn)) {
> + /*
> + * VM will be able to see the page's tags, so we must ensure
> + * they have been initialised.
> + */
> + struct page *page = pfn_to_page(pfn);
> + long i, nr_pages = compound_nr(page);
> +
> + /* if PG_mte_tagged is set, tags have already been initialised */
> + for (i = 0; i < nr_pages; i++, page++) {
> + if (!test_and_set_bit(PG_mte_tagged, &page->flags))
> + mte_clear_page_tags(page_address(page));
> + }
> + }
If this page was swapped out and mapped back in, where does the
restoring from swap happen?
I may have asked in the past, is user_mem_abort() the only path for
mapping Normal pages into stage 2?
--
Catalin
next prev parent reply other threads:[~2020-11-17 16:07 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-26 15:57 [PATCH v4 0/2] MTE support for KVM guest Steven Price
2020-10-26 15:57 ` [PATCH v4 1/2] arm64: kvm: Save/restore MTE registers Steven Price
2020-11-17 19:20 ` Marc Zyngier
2020-11-18 16:01 ` Steven Price
2020-11-18 17:02 ` Catalin Marinas
2020-11-19 12:45 ` Steven Price
2020-10-26 15:57 ` [PATCH v4 2/2] arm64: kvm: Introduce MTE VCPU feature Steven Price
2020-11-17 16:07 ` Catalin Marinas [this message]
2020-11-18 16:01 ` Steven Price
2020-11-18 16:50 ` Catalin Marinas
2020-11-18 17:05 ` Andrew Jones
2020-11-19 12:45 ` Steven Price
2020-11-19 16:24 ` Catalin Marinas
2020-11-20 9:33 ` Steven Price
2020-11-25 18:13 ` James Morse
2020-11-17 19:35 ` Marc Zyngier
2020-11-18 16:01 ` Steven Price
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