From: Will Deacon <will@kernel.org>
To: Quentin Perret <qperret@google.com>
Cc: catalin.marinas@arm.com, maz@kernel.org, james.morse@arm.com,
julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com,
android-kvm@google.com, seanjc@google.com, mate.toth-pal@arm.com,
linux-kernel@vger.kernel.org, robh+dt@kernel.org,
linux-arm-kernel@lists.infradead.org, kernel-team@android.com,
kvmarm@lists.cs.columbia.edu, tabba@google.com, ardb@kernel.org,
mark.rutland@arm.com, dbrazdil@google.com
Subject: Re: [PATCH v6 29/38] KVM: arm64: Use page-table to track page ownership
Date: Mon, 22 Mar 2021 11:27:41 +0000 [thread overview]
Message-ID: <20210322112741.GC10318@willie-the-truck> (raw)
In-Reply-To: <20210319100146.1149909-30-qperret@google.com>
On Fri, Mar 19, 2021 at 10:01:37AM +0000, Quentin Perret wrote:
> As the host stage 2 will be identity mapped, all the .hyp memory regions
> and/or memory pages donated to protected guestis will have to marked
> invalid in the host stage 2 page-table. At the same time, the hypervisor
> will need a way to track the ownership of each physical page to ensure
> memory sharing or donation between entities (host, guests, hypervisor) is
> legal.
>
> In order to enable this tracking at EL2, let's use the host stage 2
> page-table itself. The idea is to use the top bits of invalid mappings
> to store the unique identifier of the page owner. The page-table owner
> (the host) gets identifier 0 such that, at boot time, it owns the entire
> IPA space as the pgd starts zeroed.
>
> Provide kvm_pgtable_stage2_set_owner() which allows to modify the
> ownership of pages in the host stage 2. It re-uses most of the map()
> logic, but ends up creating invalid mappings instead. This impacts
> how we do refcount as we now need to count invalid mappings when they
> are used for ownership tracking.
>
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
> arch/arm64/include/asm/kvm_pgtable.h | 20 +++++
> arch/arm64/kvm/hyp/pgtable.c | 126 ++++++++++++++++++++++-----
> 2 files changed, 122 insertions(+), 24 deletions(-)
Acked-by: Will Deacon <will@kernel.org>
Will
next prev parent reply other threads:[~2021-03-22 11:28 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 10:01 [PATCH v6 00/38] KVM: arm64: Stage-2 for the host Quentin Perret
2021-03-19 10:01 ` [PATCH v6 01/38] arm64: lib: Annotate {clear,copy}_page() as position-independent Quentin Perret
2021-03-19 10:01 ` [PATCH v6 02/38] KVM: arm64: Link position-independent string routines into .hyp.text Quentin Perret
2021-03-19 10:01 ` [PATCH v6 03/38] arm64: kvm: Add standalone ticket spinlock implementation for use at hyp Quentin Perret
2021-03-19 10:01 ` [PATCH v6 04/38] KVM: arm64: Initialize kvm_nvhe_init_params early Quentin Perret
2021-03-19 10:01 ` [PATCH v6 05/38] KVM: arm64: Avoid free_page() in page-table allocator Quentin Perret
2021-03-19 10:01 ` [PATCH v6 06/38] KVM: arm64: Factor memory allocation out of pgtable.c Quentin Perret
2021-03-19 10:01 ` [PATCH v6 07/38] KVM: arm64: Introduce a BSS section for use at Hyp Quentin Perret
2021-03-19 10:01 ` [PATCH v6 08/38] KVM: arm64: Make kvm_call_hyp() a function call " Quentin Perret
2021-03-19 10:01 ` [PATCH v6 09/38] KVM: arm64: Allow using kvm_nvhe_sym() in hyp code Quentin Perret
2021-03-19 10:01 ` [PATCH v6 10/38] KVM: arm64: Introduce an early Hyp page allocator Quentin Perret
2021-03-19 10:01 ` [PATCH v6 11/38] KVM: arm64: Stub CONFIG_DEBUG_LIST at Hyp Quentin Perret
2021-03-19 10:01 ` [PATCH v6 12/38] KVM: arm64: Introduce a Hyp buddy page allocator Quentin Perret
2021-03-19 10:01 ` [PATCH v6 13/38] KVM: arm64: Enable access to sanitized CPU features at EL2 Quentin Perret
2021-03-22 11:24 ` Will Deacon
2021-03-22 13:44 ` Marc Zyngier
2021-03-22 14:19 ` Quentin Perret
2021-03-19 10:01 ` [PATCH v6 14/38] KVM: arm64: Provide __flush_dcache_area " Quentin Perret
2021-03-22 11:25 ` Will Deacon
2021-03-19 10:01 ` [PATCH v6 15/38] KVM: arm64: Factor out vector address calculation Quentin Perret
2021-03-19 10:01 ` [PATCH v6 16/38] arm64: asm: Provide set_sctlr_el2 macro Quentin Perret
2021-03-19 10:01 ` [PATCH v6 17/38] KVM: arm64: Prepare the creation of s1 mappings at EL2 Quentin Perret
2021-03-19 10:01 ` [PATCH v6 18/38] KVM: arm64: Elevate hypervisor mappings creation " Quentin Perret
2021-03-19 10:01 ` [PATCH v6 19/38] KVM: arm64: Use kvm_arch for stage 2 pgtable Quentin Perret
2021-03-19 10:01 ` [PATCH v6 20/38] KVM: arm64: Use kvm_arch in kvm_s2_mmu Quentin Perret
2021-03-19 10:01 ` [PATCH v6 21/38] KVM: arm64: Set host stage 2 using kvm_nvhe_init_params Quentin Perret
2021-03-19 10:01 ` [PATCH v6 22/38] KVM: arm64: Refactor kvm_arm_setup_stage2() Quentin Perret
2021-03-19 10:01 ` [PATCH v6 23/38] KVM: arm64: Refactor __load_guest_stage2() Quentin Perret
2021-03-19 10:01 ` [PATCH v6 24/38] KVM: arm64: Refactor __populate_fault_info() Quentin Perret
2021-03-19 10:01 ` [PATCH v6 25/38] KVM: arm64: Make memcache anonymous in pgtable allocator Quentin Perret
2021-03-19 10:01 ` [PATCH v6 26/38] KVM: arm64: Reserve memory for host stage 2 Quentin Perret
2021-03-19 10:01 ` [PATCH v6 27/38] KVM: arm64: Sort the hypervisor memblocks Quentin Perret
2021-03-19 10:01 ` [PATCH v6 28/38] KVM: arm64: Always zero invalid PTEs Quentin Perret
2021-03-19 10:01 ` [PATCH v6 29/38] KVM: arm64: Use page-table to track page ownership Quentin Perret
2021-03-22 11:27 ` Will Deacon [this message]
2021-03-19 10:01 ` [PATCH v6 30/38] KVM: arm64: Refactor the *_map_set_prot_attr() helpers Quentin Perret
2021-03-19 10:01 ` [PATCH v6 31/38] KVM: arm64: Add kvm_pgtable_stage2_find_range() Quentin Perret
2021-03-19 10:01 ` [PATCH v6 32/38] KVM: arm64: Introduce KVM_PGTABLE_S2_NOFWB stage 2 flag Quentin Perret
2021-03-22 12:19 ` Will Deacon
2021-03-19 10:01 ` [PATCH v6 33/38] KVM: arm64: Introduce KVM_PGTABLE_S2_IDMAP " Quentin Perret
2021-03-22 11:33 ` Will Deacon
2021-03-19 10:01 ` [PATCH v6 34/38] KVM: arm64: Provide sanitized mmfr* registers at EL2 Quentin Perret
2021-03-19 10:01 ` [PATCH v6 35/38] KVM: arm64: Wrap the host with a stage 2 Quentin Perret
2021-03-19 10:01 ` [PATCH v6 36/38] KVM: arm64: Page-align the .hyp sections Quentin Perret
2021-03-19 10:01 ` [PATCH v6 37/38] KVM: arm64: Disable PMU support in protected mode Quentin Perret
2021-03-19 10:01 ` [PATCH v6 38/38] KVM: arm64: Protect the .hyp sections from the host Quentin Perret
2021-03-25 11:13 ` [PATCH v6 00/38] KVM: arm64: Stage-2 for " Marc Zyngier
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