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From: Quentin Perret <qperret@google.com>
To: Marc Zyngier <maz@kernel.org>,
	Oliver Upton <oliver.upton@linux.dev>,
	 Joey Gouly <joey.gouly@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	 Zenghui Yu <yuzenghui@huawei.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	 Will Deacon <will@kernel.org>
Cc: Vincent Donnefort <vdonnefort@google.com>,
	Quentin Perret <qperret@google.com>,
	 linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
	 linux-kernel@vger.kernel.org
Subject: [PATCH 2/6] KVM: arm64: Use 0b11 for encoding PKVM_NOPAGE
Date: Thu, 27 Feb 2025 00:33:06 +0000	[thread overview]
Message-ID: <20250227003310.367350-3-qperret@google.com> (raw)
In-Reply-To: <20250227003310.367350-1-qperret@google.com>

The page ownership state encoded as 0b11 is currently considered
reserved for future use, and PKVM_NOPAGE uses bit 2. In order to
simplify the relocation of the hyp ownership state into the
vmemmap in later patches, let's use the 'reserved' encoding for
the PKVM_NOPAGE state. The struct hyp_page layout isn't guaranteed
stable at all, so there is no real reason to have 'reserved' encodings.

No functional changes intended.

Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/hyp/include/nvhe/memory.h | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h
index 34233d586060..642b5e05fe77 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/memory.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h
@@ -13,18 +13,15 @@
  *   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		= BIT(0),
 	PKVM_PAGE_SHARED_BORROWED	= BIT(1),
-	__PKVM_PAGE_RESERVED		= BIT(0) | BIT(1),
 
 	/* Meta-states which aren't encoded directly in the PTE's SW bits */
-	PKVM_NOPAGE			= BIT(2),
+	PKVM_NOPAGE			= BIT(0) | BIT(1),
 };
-#define PKVM_PAGE_META_STATES_MASK	(~__PKVM_PAGE_RESERVED)
 
 #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,
-- 
2.48.1.658.g4767266eb4-goog


  parent reply	other threads:[~2025-02-27  0:33 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-02-27  0:33 [PATCH 0/6] Move pKVM ownership state to hyp_vmemmap Quentin Perret
2025-02-27  0:33 ` [PATCH 1/6] KVM: arm64: Track SVE state in the hypervisor vcpu structure Quentin Perret
2025-02-27  0:33 ` Quentin Perret [this message]
2025-03-14 11:07   ` [PATCH 2/6] KVM: arm64: Use 0b11 for encoding PKVM_NOPAGE Marc Zyngier
2025-03-14 14:13     ` Quentin Perret
2025-03-16 11:03       ` Marc Zyngier
2025-02-27  0:33 ` [PATCH 3/6] KVM: arm64: Introduce {get,set}_host_state() helpers Quentin Perret
2025-02-27  0:33 ` [PATCH 4/6] KVM: arm64: Move hyp state to hyp_vmemmap Quentin Perret
2025-03-03  9:47   ` Vincent Donnefort
2025-03-13 19:13     ` Quentin Perret
2025-03-14 11:31   ` Marc Zyngier
2025-03-14 14:06     ` Quentin Perret
2025-03-16 11:08       ` Marc Zyngier
2025-02-27  0:33 ` [PATCH 5/6] KVM: arm64: Defer EL2 stage-1 mapping on share Quentin Perret
2025-02-27  0:33 ` [PATCH 6/6] KVM: arm64: Unconditionally cross check hyp state Quentin Perret
2025-03-16 11:12 ` [PATCH 0/6] Move pKVM ownership state to hyp_vmemmap Marc Zyngier

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