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From: Quentin Perret <qperret@google.com>
To: maz@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com,
	suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
	ardb@kernel.org, qwandor@google.com, tabba@google.com,
	dbrazdil@google.com, kernel-team@android.com,
	Quentin Perret <qperret@google.com>
Subject: [PATCH v3 09/21] KVM: arm64: Tolerate re-creating hyp mappings to set software bits
Date: Thu, 29 Jul 2021 14:28:06 +0100	[thread overview]
Message-ID: <20210729132818.4091769-10-qperret@google.com> (raw)
In-Reply-To: <20210729132818.4091769-1-qperret@google.com>

The current hypervisor stage-1 mapping code doesn't allow changing an
existing valid mapping. Relax this condition by allowing changes that
only target software bits, as that will soon be needed to annotate shared
pages.

Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/hyp/pgtable.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 1ee1168ac32d..2689fcb7901d 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -362,6 +362,21 @@ static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
 	return 0;
 }
 
+static bool hyp_pte_needs_update(kvm_pte_t old, kvm_pte_t new)
+{
+	/*
+	 * Tolerate KVM recreating the exact same mapping, or changing software
+	 * bits if the existing mapping was valid.
+	 */
+	if (old == new)
+		return false;
+
+	if (!kvm_pte_valid(old))
+		return true;
+
+	return !WARN_ON((old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW);
+}
+
 static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
 				    kvm_pte_t *ptep, struct hyp_map_data *data)
 {
@@ -371,9 +386,8 @@ static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
 	if (!kvm_block_mapping_supported(addr, end, phys, level))
 		return false;
 
-	/* Tolerate KVM recreating the exact same mapping */
 	new = kvm_init_valid_leaf_pte(phys, data->attr, level);
-	if (old != new && !WARN_ON(kvm_pte_valid(old)))
+	if (hyp_pte_needs_update(old, new))
 		smp_store_release(ptep, new);
 
 	data->phys += granule;
-- 
2.32.0.432.gabb21c7263-goog


WARNING: multiple messages have this Message-ID
From: Quentin Perret <qperret@google.com>
To: maz@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com,
	 suzuki.poulose@arm.com, catalin.marinas@arm.com,
	will@kernel.org
Cc: qwandor@google.com, linux-kernel@vger.kernel.org,
	kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org, kernel-team@android.com
Subject: [PATCH v3 09/21] KVM: arm64: Tolerate re-creating hyp mappings to set software bits
Date: Thu, 29 Jul 2021 14:28:06 +0100	[thread overview]
Message-ID: <20210729132818.4091769-10-qperret@google.com> (raw)
In-Reply-To: <20210729132818.4091769-1-qperret@google.com>

The current hypervisor stage-1 mapping code doesn't allow changing an
existing valid mapping. Relax this condition by allowing changes that
only target software bits, as that will soon be needed to annotate shared
pages.

Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/hyp/pgtable.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 1ee1168ac32d..2689fcb7901d 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -362,6 +362,21 @@ static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
 	return 0;
 }
 
+static bool hyp_pte_needs_update(kvm_pte_t old, kvm_pte_t new)
+{
+	/*
+	 * Tolerate KVM recreating the exact same mapping, or changing software
+	 * bits if the existing mapping was valid.
+	 */
+	if (old == new)
+		return false;
+
+	if (!kvm_pte_valid(old))
+		return true;
+
+	return !WARN_ON((old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW);
+}
+
 static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
 				    kvm_pte_t *ptep, struct hyp_map_data *data)
 {
@@ -371,9 +386,8 @@ static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
 	if (!kvm_block_mapping_supported(addr, end, phys, level))
 		return false;
 
-	/* Tolerate KVM recreating the exact same mapping */
 	new = kvm_init_valid_leaf_pte(phys, data->attr, level);
-	if (old != new && !WARN_ON(kvm_pte_valid(old)))
+	if (hyp_pte_needs_update(old, new))
 		smp_store_release(ptep, new);
 
 	data->phys += granule;
-- 
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: Quentin Perret <qperret@google.com>
To: maz@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com,
	 suzuki.poulose@arm.com, catalin.marinas@arm.com,
	will@kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu,  linux-kernel@vger.kernel.org,
	ardb@kernel.org, qwandor@google.com,  tabba@google.com,
	dbrazdil@google.com, kernel-team@android.com,
	 Quentin Perret <qperret@google.com>
Subject: [PATCH v3 09/21] KVM: arm64: Tolerate re-creating hyp mappings to set software bits
Date: Thu, 29 Jul 2021 14:28:06 +0100	[thread overview]
Message-ID: <20210729132818.4091769-10-qperret@google.com> (raw)
In-Reply-To: <20210729132818.4091769-1-qperret@google.com>

The current hypervisor stage-1 mapping code doesn't allow changing an
existing valid mapping. Relax this condition by allowing changes that
only target software bits, as that will soon be needed to annotate shared
pages.

Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/hyp/pgtable.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 1ee1168ac32d..2689fcb7901d 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -362,6 +362,21 @@ static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
 	return 0;
 }
 
+static bool hyp_pte_needs_update(kvm_pte_t old, kvm_pte_t new)
+{
+	/*
+	 * Tolerate KVM recreating the exact same mapping, or changing software
+	 * bits if the existing mapping was valid.
+	 */
+	if (old == new)
+		return false;
+
+	if (!kvm_pte_valid(old))
+		return true;
+
+	return !WARN_ON((old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW);
+}
+
 static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
 				    kvm_pte_t *ptep, struct hyp_map_data *data)
 {
@@ -371,9 +386,8 @@ static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
 	if (!kvm_block_mapping_supported(addr, end, phys, level))
 		return false;
 
-	/* Tolerate KVM recreating the exact same mapping */
 	new = kvm_init_valid_leaf_pte(phys, data->attr, level);
-	if (old != new && !WARN_ON(kvm_pte_valid(old)))
+	if (hyp_pte_needs_update(old, new))
 		smp_store_release(ptep, new);
 
 	data->phys += granule;
-- 
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

  parent reply	other threads:[~2021-07-29 13:28 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 ` Quentin Perret [this message]
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
2021-08-02  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
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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