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From: Fuad Tabba <tabba@google.com>
To: Quentin Perret <qperret@google.com>
Cc: maz@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com,
	suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
	ardb@kernel.org, qwandor@google.com, dbrazdil@google.com,
	kernel-team@android.com
Subject: Re: [PATCH v3 12/21] KVM: arm64: Add helpers to tag shared pages in SW bits
Date: Mon, 2 Aug 2021 12:30:25 +0200	[thread overview]
Message-ID: <CA+EHjTzT+aMGkc5cEwGT+05z6aGmbLi0DBetBGXLh3GFY2GXgQ@mail.gmail.com> (raw)
In-Reply-To: <20210729132818.4091769-13-qperret@google.com>

Hi Quentin,


On Thu, Jul 29, 2021 at 3:28 PM Quentin Perret <qperret@google.com> wrote:
>
> We will soon start annotating shared pages in page-tables in nVHE
> protected mode. Define all the states in which a page can be (owned,
> shared and owned, shared and borrowed), and provide helpers allowing to
> convert this into SW bits annotations using the matching prot
> attributes.
>
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
>  arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 26 +++++++++++++++++++
>  1 file changed, 26 insertions(+)
>
> diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> index 9c227d87c36d..ae355bfd8c01 100644
> --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> @@ -12,6 +12,32 @@
>  #include <asm/virt.h>
>  #include <nvhe/spinlock.h>
>
> +/*
> + * SW bits 0-1 are reserved to track the memory ownership state of each page:
> + *   00: The page is owned solely by the page-table owner.

nit: solely -> exclusively, because "exclusive" is the more common
term in context of shared resources

> + *   01: The page is owned by the page-table owner, but is shared
> + *       with another entity.
> + *   10: The page is shared with, but not owned by the page-table owner.
> + *   11: Reserved for future use (lending).
> + */
> +enum pkvm_page_state {
> +       PKVM_PAGE_OWNED                 = 0ULL,
> +       PKVM_PAGE_SHARED_OWNED          = KVM_PGTABLE_PROT_SW0,
> +       PKVM_PAGE_SHARED_BORROWED       = KVM_PGTABLE_PROT_SW1,
> +};
> +
> +#define PKVM_PAGE_STATE_PROT_MASK      (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1)
> +static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot,
> +                                                enum pkvm_page_state state)
> +{
> +       return (prot & ~PKVM_PAGE_STATE_PROT_MASK) | state;
> +}
> +
> +static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot)
> +{
> +       return prot & PKVM_PAGE_STATE_PROT_MASK;
> +}
> +

I think that this encoding is pretty neat and easy to follow.

Reviewed-by: Fuad Tabba <tabba@google.com>

Thanks,
/fuad

>  struct host_kvm {
>         struct kvm_arch arch;
>         struct kvm_pgtable pgt;
> --
> 2.32.0.432.gabb21c7263-goog
>

WARNING: multiple messages have this Message-ID
From: Fuad Tabba <tabba@google.com>
To: Quentin Perret <qperret@google.com>
Cc: kernel-team@android.com, qwandor@google.com, maz@kernel.org,
	linux-kernel@vger.kernel.org, catalin.marinas@arm.com,
	will@kernel.org, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 12/21] KVM: arm64: Add helpers to tag shared pages in SW bits
Date: Mon, 2 Aug 2021 12:30:25 +0200	[thread overview]
Message-ID: <CA+EHjTzT+aMGkc5cEwGT+05z6aGmbLi0DBetBGXLh3GFY2GXgQ@mail.gmail.com> (raw)
In-Reply-To: <20210729132818.4091769-13-qperret@google.com>

Hi Quentin,


On Thu, Jul 29, 2021 at 3:28 PM Quentin Perret <qperret@google.com> wrote:
>
> We will soon start annotating shared pages in page-tables in nVHE
> protected mode. Define all the states in which a page can be (owned,
> shared and owned, shared and borrowed), and provide helpers allowing to
> convert this into SW bits annotations using the matching prot
> attributes.
>
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
>  arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 26 +++++++++++++++++++
>  1 file changed, 26 insertions(+)
>
> diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> index 9c227d87c36d..ae355bfd8c01 100644
> --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> @@ -12,6 +12,32 @@
>  #include <asm/virt.h>
>  #include <nvhe/spinlock.h>
>
> +/*
> + * SW bits 0-1 are reserved to track the memory ownership state of each page:
> + *   00: The page is owned solely by the page-table owner.

nit: solely -> exclusively, because "exclusive" is the more common
term in context of shared resources

> + *   01: The page is owned by the page-table owner, but is shared
> + *       with another entity.
> + *   10: The page is shared with, but not owned by the page-table owner.
> + *   11: Reserved for future use (lending).
> + */
> +enum pkvm_page_state {
> +       PKVM_PAGE_OWNED                 = 0ULL,
> +       PKVM_PAGE_SHARED_OWNED          = KVM_PGTABLE_PROT_SW0,
> +       PKVM_PAGE_SHARED_BORROWED       = KVM_PGTABLE_PROT_SW1,
> +};
> +
> +#define PKVM_PAGE_STATE_PROT_MASK      (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1)
> +static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot,
> +                                                enum pkvm_page_state state)
> +{
> +       return (prot & ~PKVM_PAGE_STATE_PROT_MASK) | state;
> +}
> +
> +static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot)
> +{
> +       return prot & PKVM_PAGE_STATE_PROT_MASK;
> +}
> +

I think that this encoding is pretty neat and easy to follow.

Reviewed-by: Fuad Tabba <tabba@google.com>

Thanks,
/fuad

>  struct host_kvm {
>         struct kvm_arch arch;
>         struct kvm_pgtable pgt;
> --
> 2.32.0.432.gabb21c7263-goog
>
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID
From: Fuad Tabba <tabba@google.com>
To: Quentin Perret <qperret@google.com>
Cc: maz@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com,
	 suzuki.poulose@arm.com, catalin.marinas@arm.com,
	will@kernel.org,  linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu,  linux-kernel@vger.kernel.org,
	ardb@kernel.org, qwandor@google.com,  dbrazdil@google.com,
	kernel-team@android.com
Subject: Re: [PATCH v3 12/21] KVM: arm64: Add helpers to tag shared pages in SW bits
Date: Mon, 2 Aug 2021 12:30:25 +0200	[thread overview]
Message-ID: <CA+EHjTzT+aMGkc5cEwGT+05z6aGmbLi0DBetBGXLh3GFY2GXgQ@mail.gmail.com> (raw)
In-Reply-To: <20210729132818.4091769-13-qperret@google.com>

Hi Quentin,


On Thu, Jul 29, 2021 at 3:28 PM Quentin Perret <qperret@google.com> wrote:
>
> We will soon start annotating shared pages in page-tables in nVHE
> protected mode. Define all the states in which a page can be (owned,
> shared and owned, shared and borrowed), and provide helpers allowing to
> convert this into SW bits annotations using the matching prot
> attributes.
>
> Signed-off-by: Quentin Perret <qperret@google.com>
> ---
>  arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 26 +++++++++++++++++++
>  1 file changed, 26 insertions(+)
>
> diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> index 9c227d87c36d..ae355bfd8c01 100644
> --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
> @@ -12,6 +12,32 @@
>  #include <asm/virt.h>
>  #include <nvhe/spinlock.h>
>
> +/*
> + * SW bits 0-1 are reserved to track the memory ownership state of each page:
> + *   00: The page is owned solely by the page-table owner.

nit: solely -> exclusively, because "exclusive" is the more common
term in context of shared resources

> + *   01: The page is owned by the page-table owner, but is shared
> + *       with another entity.
> + *   10: The page is shared with, but not owned by the page-table owner.
> + *   11: Reserved for future use (lending).
> + */
> +enum pkvm_page_state {
> +       PKVM_PAGE_OWNED                 = 0ULL,
> +       PKVM_PAGE_SHARED_OWNED          = KVM_PGTABLE_PROT_SW0,
> +       PKVM_PAGE_SHARED_BORROWED       = KVM_PGTABLE_PROT_SW1,
> +};
> +
> +#define PKVM_PAGE_STATE_PROT_MASK      (KVM_PGTABLE_PROT_SW0 | KVM_PGTABLE_PROT_SW1)
> +static inline enum kvm_pgtable_prot pkvm_mkstate(enum kvm_pgtable_prot prot,
> +                                                enum pkvm_page_state state)
> +{
> +       return (prot & ~PKVM_PAGE_STATE_PROT_MASK) | state;
> +}
> +
> +static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot)
> +{
> +       return prot & PKVM_PAGE_STATE_PROT_MASK;
> +}
> +

I think that this encoding is pretty neat and easy to follow.

Reviewed-by: Fuad Tabba <tabba@google.com>

Thanks,
/fuad

>  struct host_kvm {
>         struct kvm_arch arch;
>         struct kvm_pgtable pgt;
> --
> 2.32.0.432.gabb21c7263-goog
>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2021-08-02 10:31 UTC|newest]

Thread overview: 135+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-29 13:27 [PATCH v3 00/21] Track shared pages at EL2 in protected mode Quentin Perret
2021-07-29 13:27 ` Quentin Perret
2021-07-29 13:27 ` Quentin Perret
2021-07-29 13:27 ` [PATCH v3 01/21] KVM: arm64: Add hyp_spin_is_locked() for basic locking assertions at EL2 Quentin Perret
2021-07-29 13:27   ` Quentin Perret
2021-07-29 13:27   ` Quentin Perret
2021-07-29 13:27 ` [PATCH v3 02/21] KVM: arm64: Introduce hyp_assert_lock_held() Quentin Perret
2021-07-29 13:27   ` Quentin Perret
2021-07-29 13:27   ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 03/21] KVM: arm64: Provide the host_stage2_try() helper macro Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02  9:36   ` Fuad Tabba
2021-08-02  9:36     ` Fuad Tabba
2021-08-02  9:36     ` Fuad Tabba
2021-07-29 13:28 ` [PATCH v3 04/21] KVM: arm64: Introduce helper to retrieve a PTE and its level Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 05/21] KVM: arm64: Expose page-table helpers Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 06/21] KVM: arm64: Optimize host memory aborts Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02  9:37   ` Fuad Tabba
2021-08-02  9:37     ` Fuad Tabba
2021-08-02  9:37     ` Fuad Tabba
2021-07-29 13:28 ` [PATCH v3 07/21] KVM: arm64: Rename KVM_PTE_LEAF_ATTR_S2_IGNORED Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02  9:37   ` Fuad Tabba
2021-08-02  9:37     ` Fuad Tabba
2021-08-02  9:37     ` Fuad Tabba
2021-07-29 13:28 ` [PATCH v3 08/21] KVM: arm64: Don't overwrite software bits with owner id Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02  9:38   ` Fuad Tabba
2021-08-02  9:38     ` Fuad Tabba
2021-08-02  9:38     ` Fuad Tabba
2021-07-29 13:28 ` [PATCH v3 09/21] KVM: arm64: Tolerate re-creating hyp mappings to set software bits Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02  9:50   ` Fuad Tabba
2021-08-02  9:50     ` Fuad Tabba
2021-08-02  9:50     ` Fuad Tabba
2021-07-29 13:28 ` [PATCH v3 10/21] KVM: arm64: Enable forcing page-level stage-2 mappings Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02  9:49   ` Fuad Tabba
2021-08-02  9:49     ` Fuad Tabba
2021-08-02  9:49     ` Fuad Tabba
2021-08-03 10:13     ` Quentin Perret
2021-08-03 10:13       ` Quentin Perret
2021-08-03 10:13       ` Quentin Perret
2021-08-03 10:43       ` Fuad Tabba
2021-08-03 10:43         ` Fuad Tabba
2021-08-03 10:43         ` Fuad Tabba
2021-07-29 13:28 ` [PATCH v3 11/21] KVM: arm64: Allow populating software bits Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 12/21] KVM: arm64: Add helpers to tag shared pages in SW bits Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02 10:30   ` Fuad Tabba [this message]
2021-08-02 10:30     ` Fuad Tabba
2021-08-02 10:30     ` Fuad Tabba
2021-07-29 13:28 ` [PATCH v3 13/21] KVM: arm64: Expose host stage-2 manipulation helpers Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02 11:13   ` Fuad Tabba
2021-08-02 11:13     ` Fuad Tabba
2021-08-02 11:13     ` Fuad Tabba
2021-08-03 10:20     ` Quentin Perret
2021-08-03 10:20       ` Quentin Perret
2021-08-03 10:20       ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 14/21] KVM: arm64: Expose pkvm_hyp_id Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 15/21] KVM: arm64: Introduce addr_is_memory() Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02 14:52   ` Fuad Tabba
2021-08-02 14:52     ` Fuad Tabba
2021-08-02 14:52     ` Fuad Tabba
2021-08-03 10:23     ` Quentin Perret
2021-08-03 10:23       ` Quentin Perret
2021-08-03 10:23       ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 16/21] KVM: arm64: Enable retrieving protections attributes of PTEs Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-02 14:52   ` Fuad Tabba
2021-08-02 14:52     ` Fuad Tabba
2021-08-02 14:52     ` Fuad Tabba
2021-08-03 10:24     ` Quentin Perret
2021-08-03 10:24       ` Quentin Perret
2021-08-03 10:24       ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 17/21] KVM: arm64: Mark host bss and rodata section as shared Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-03  5:02   ` Fuad Tabba
2021-08-03  5:02     ` Fuad Tabba
2021-08-03  5:02     ` Fuad Tabba
2021-08-03 10:34     ` Quentin Perret
2021-08-03 10:34       ` Quentin Perret
2021-08-03 10:34       ` Quentin Perret
2021-08-03 10:54       ` Fuad Tabba
2021-08-03 10:54         ` Fuad Tabba
2021-08-03 10:54         ` Fuad Tabba
2021-07-29 13:28 ` [PATCH v3 18/21] KVM: arm64: Remove __pkvm_mark_hyp Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 19/21] KVM: arm64: Refactor protected nVHE stage-1 locking Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-03  5:31   ` Fuad Tabba
2021-08-03  5:31     ` Fuad Tabba
2021-08-03  5:31     ` Fuad Tabba
2021-08-03 10:37     ` Quentin Perret
2021-08-03 10:37       ` Quentin Perret
2021-08-03 10:37       ` Quentin Perret
2021-08-03 10:51       ` Fuad Tabba
2021-08-03 10:51         ` Fuad Tabba
2021-08-03 10:51         ` Fuad Tabba
2021-07-29 13:28 ` [PATCH v3 20/21] KVM: arm64: Restrict EL2 stage-1 changes in protected mode Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-08-03  8:22   ` Fuad Tabba
2021-08-03  8:22     ` Fuad Tabba
2021-08-03  8:22     ` Fuad Tabba
2021-08-03 10:43     ` Quentin Perret
2021-08-03 10:43       ` Quentin Perret
2021-08-03 10:43       ` Quentin Perret
2021-07-29 13:28 ` [PATCH v3 21/21] KVM: arm64: Make __pkvm_create_mappings static Quentin Perret
2021-07-29 13:28   ` Quentin Perret
2021-07-29 13:28   ` Quentin Perret

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