From: Quentin Perret <qperret@google.com>
To: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
kernel-team@android.com
Subject: Re: [PATCH v3 07/15] KVM: arm64: Introduce kvm_share_hyp()
Date: Fri, 10 Dec 2021 14:37:21 +0000 [thread overview]
Message-ID: <YbNmIfeRdgaQNf+l@google.com> (raw)
In-Reply-To: <20211209111309.GB1912@willie-the-truck>
On Thursday 09 Dec 2021 at 11:13:10 (+0000), Will Deacon wrote:
> On Wed, Dec 01, 2021 at 05:04:01PM +0000, Quentin Perret wrote:
> > The create_hyp_mappings() function can currently be called at any point
> > in time. However, its behaviour in protected mode changes widely
> > depending on when it is being called. Prior to KVM init, it is used to
> > create the temporary page-table used to bring-up the hypervisor, and
> > later on it is transparently turned into a 'share' hypercall when the
> > kernel has lost control over the hypervisor stage-1. In order to prepare
> > the ground for also unsharing pages with the hypervisor during guest
> > teardown, introduce a kvm_share_hyp() function to make it clear in which
> > places a share hypercall should be expected, as we will soon need a
> > matching unshare hypercall in all those places.
> >
> > Signed-off-by: Quentin Perret <qperret@google.com>
> > ---
> > arch/arm64/include/asm/kvm_mmu.h | 1 +
> > arch/arm64/kvm/arm.c | 4 ++--
> > arch/arm64/kvm/fpsimd.c | 2 +-
> > arch/arm64/kvm/mmu.c | 27 +++++++++++++++++++++------
> > arch/arm64/kvm/reset.c | 2 +-
> > 5 files changed, 26 insertions(+), 10 deletions(-)
>
> [...]
>
> > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> > index f8f1096a297f..fd868fb9d922 100644
> > --- a/arch/arm64/kvm/mmu.c
> > +++ b/arch/arm64/kvm/mmu.c
> > @@ -299,6 +299,25 @@ static int pkvm_share_hyp(phys_addr_t start, phys_addr_t end)
> > return 0;
> > }
> >
> > +int kvm_share_hyp(void *from, void *to)
> > +{
> > + if (is_kernel_in_hyp_mode())
> > + return 0;
> > +
> > + /*
> > + * The share hcall maps things in the 'fixed-offset' region of the hyp
> > + * VA space, so we can only share physically contiguous data-structures
> > + * for now.
> > + */
> > + if (is_vmalloc_addr(from) || is_vmalloc_addr(to))
> > + return -EINVAL;
>
> If we're adding these sanity checks, perhaps is_vmalloc_or_module_addr()
> would be worth using instead?
Ack, I'll fix that up.
next prev parent reply other threads:[~2021-12-10 14:37 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-01 17:03 [PATCH v3 00/15] KVM: arm64: Introduce kvm_share_hyp() Quentin Perret
2021-12-01 17:03 ` [PATCH v3 01/15] KVM: arm64: Check if running in VHE from kvm_host_owns_hyp_mappings() Quentin Perret
2021-12-09 10:10 ` Will Deacon
2021-12-10 13:37 ` Quentin Perret
2021-12-01 17:03 ` [PATCH v3 02/15] KVM: arm64: Provide {get,put}_page() stubs for early hyp allocator Quentin Perret
2021-12-09 10:12 ` Will Deacon
2021-12-01 17:03 ` [PATCH v3 03/15] KVM: arm64: Refcount hyp stage-1 pgtable pages Quentin Perret
2021-12-09 10:29 ` Will Deacon
2021-12-10 14:34 ` Quentin Perret
2021-12-13 12:53 ` Will Deacon
2021-12-01 17:03 ` [PATCH v3 04/15] KVM: arm64: Fixup hyp stage-1 refcount Quentin Perret
2021-12-09 11:09 ` Will Deacon
2021-12-01 17:03 ` [PATCH v3 05/15] KVM: arm64: Hook up ->page_count() for hypervisor stage-1 page-table Quentin Perret
2021-12-01 17:04 ` [PATCH v3 06/15] KVM: arm64: Implement kvm_pgtable_hyp_unmap() at EL2 Quentin Perret
2021-12-07 14:47 ` Andrew Walbran
2021-12-08 9:51 ` Quentin Perret
2021-12-08 14:40 ` Andrew Walbran
2021-12-15 16:02 ` Quentin Perret
2021-12-01 17:04 ` [PATCH v3 07/15] KVM: arm64: Introduce kvm_share_hyp() Quentin Perret
2021-12-09 11:13 ` Will Deacon
2021-12-10 14:37 ` Quentin Perret [this message]
2021-12-01 17:04 ` [PATCH v3 08/15] KVM: arm64: pkvm: Refcount the pages shared with EL2 Quentin Perret
2021-12-09 11:16 ` Will Deacon
2021-12-01 17:04 ` [PATCH v3 09/15] KVM: arm64: Extend pkvm_page_state enumeration to handle absent pages Quentin Perret
2021-12-14 14:47 ` Andrew Walbran
2021-12-01 17:04 ` [PATCH v3 10/15] KVM: arm64: Introduce wrappers for host and hyp spin lock accessors Quentin Perret
2021-12-14 14:48 ` Andrew Walbran
2021-12-14 14:52 ` Will Deacon
2021-12-01 17:04 ` [PATCH v3 11/15] KVM: arm64: Implement do_share() helper for sharing memory Quentin Perret
2021-12-10 15:18 ` Andrew Walbran
2021-12-01 17:04 ` [PATCH v3 12/15] KVM: arm64: Implement __pkvm_host_share_hyp() using do_share() Quentin Perret
2021-12-01 17:04 ` [PATCH v3 13/15] KVM: arm64: Implement do_unshare() helper for unsharing memory Quentin Perret
2021-12-10 15:08 ` Andrew Walbran
2021-12-01 17:04 ` [PATCH v3 14/15] KVM: arm64: Expose unshare hypercall to the host Quentin Perret
2021-12-01 17:04 ` [PATCH v3 15/15] KVM: arm64: pkvm: Unshare guest structs during teardown Quentin Perret
2021-12-09 11:22 ` Will Deacon
2021-12-10 14:48 ` Quentin Perret
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