[PATCH v4 09/10] arm64: ptdump: Interpret pKVM ownership annotations

Sebastian Ene sebastianene at google.com
Mon Dec 18 05:58:59 PST 2023


When pKVM is enabled the software bits are used to keep track of the
page sharing state. Interepret these fields when pKVM is enabled and
print the sharing state. Move the definitions to common pagetable
header.

Signed-off-by: Sebastian Ene <sebastianene at google.com>
---
 arch/arm64/include/asm/kvm_pgtable.h          | 26 ++++++++++
 arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 26 ----------
 arch/arm64/kvm/ptdump.c                       | 47 +++++++++++++++++--
 3 files changed, 69 insertions(+), 30 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 37f2a8532..7f654d4aa 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -87,6 +87,13 @@ typedef u64 kvm_pte_t;
  */
 #define KVM_INVALID_PTE_LOCKED		BIT(10)
 
+/* This corresponds to page-table locking order */
+enum pkvm_component_id {
+	PKVM_ID_HOST,
+	PKVM_ID_HYP,
+	PKVM_ID_FFA,
+};
+
 static inline bool kvm_pte_valid(kvm_pte_t pte)
 {
 	return pte & KVM_PTE_VALID;
@@ -230,6 +237,25 @@ enum kvm_pgtable_prot {
 	KVM_PGTABLE_PROT_SW3			= BIT(58),
 };
 
+/*
+ * SW bits 0-1 are reserved to track the memory ownership state of each page:
+ *   00: The page is owned exclusively by the page-table owner.
+ *   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,
+	__PKVM_PAGE_RESERVED		= KVM_PGTABLE_PROT_SW0 |
+					  KVM_PGTABLE_PROT_SW1,
+
+	/* Meta-states which aren't encoded directly in the PTE's SW bits */
+	PKVM_NOPAGE,
+};
+
 #define KVM_PGTABLE_PROT_RW	(KVM_PGTABLE_PROT_R | KVM_PGTABLE_PROT_W)
 #define KVM_PGTABLE_PROT_RWX	(KVM_PGTABLE_PROT_RW | KVM_PGTABLE_PROT_X)
 
diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index ca8f76915..677686b86 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -14,25 +14,6 @@
 #include <nvhe/pkvm.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 exclusively by the page-table owner.
- *   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,
-	__PKVM_PAGE_RESERVED		= KVM_PGTABLE_PROT_SW0 |
-					  KVM_PGTABLE_PROT_SW1,
-
-	/* Meta-states which aren't encoded directly in the PTE's SW bits */
-	PKVM_NOPAGE,
-};
-
 #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)
@@ -53,13 +34,6 @@ struct host_mmu {
 };
 extern struct host_mmu host_mmu;
 
-/* This corresponds to page-table locking order */
-enum pkvm_component_id {
-	PKVM_ID_HOST,
-	PKVM_ID_HYP,
-	PKVM_ID_FFA,
-};
-
 extern unsigned long hyp_nr_cpus;
 
 int __pkvm_prot_finalize(void);
diff --git a/arch/arm64/kvm/ptdump.c b/arch/arm64/kvm/ptdump.c
index 0ad7944e5..4296e739f 100644
--- a/arch/arm64/kvm/ptdump.c
+++ b/arch/arm64/kvm/ptdump.c
@@ -52,6 +52,11 @@ static bool is_fwb_enabled(const struct pg_state *m)
 	return fwb_enabled;
 }
 
+static bool is_pkvm_enabled(const struct pg_state *m)
+{
+	return is_protected_kvm_enabled();
+}
+
 static const struct prot_bits stage2_pte_bits[] = {
 	{
 		.mask	= PTE_VALID,
@@ -113,22 +118,56 @@ static const struct prot_bits stage2_pte_bits[] = {
 		.val	= PTE_S2_MEMATTR(MT_S2_FWB_NORMAL) | PTE_VALID,
 		.set	= "MEM/NORMAL FWB",
 		.feature_on	= is_fwb_enabled,
+	}, {
+		.mask	= KVM_INVALID_PTE_OWNER_MASK | PTE_VALID,
+		.val	= FIELD_PREP_CONST(KVM_INVALID_PTE_OWNER_MASK,
+					   PKVM_ID_HYP),
+		.set	= "HYP",
+	}, {
+		.mask	= KVM_INVALID_PTE_OWNER_MASK | PTE_VALID,
+		.val	= FIELD_PREP_CONST(KVM_INVALID_PTE_OWNER_MASK,
+					   PKVM_ID_FFA),
+		.set	= "FF-A",
+	}, {
+		.mask	= __PKVM_PAGE_RESERVED | PTE_VALID,
+		.val	= PKVM_PAGE_OWNED | PTE_VALID,
+		.set	= "PKVM_PAGE_OWNED",
+		.feature_on	= is_pkvm_enabled,
+	}, {
+		.mask   = __PKVM_PAGE_RESERVED | PTE_VALID,
+		.val	= PKVM_PAGE_SHARED_OWNED | PTE_VALID,
+		.set	= "PKVM_PAGE_SHARED_OWNED",
+		.feature_on     = is_pkvm_enabled,
+	}, {
+		.mask	= __PKVM_PAGE_RESERVED | PTE_VALID,
+		.val	= PKVM_PAGE_SHARED_BORROWED | PTE_VALID,
+		.set	= "PKVM_PAGE_SHARED_BORROWED",
+		.feature_on     = is_pkvm_enabled,
+	}, {
+		.mask	= PKVM_NOPAGE | PTE_VALID,
+		.val	= PKVM_NOPAGE,
+		.set	= "PKVM_NOPAGE",
+		.feature_on     = is_pkvm_enabled,
 	}, {
 		.mask	= KVM_PGTABLE_PROT_SW0,
 		.val	= KVM_PGTABLE_PROT_SW0,
-		.set	= "SW0", /* PKVM_PAGE_SHARED_OWNED */
+		.set    = "SW0",
+		.feature_off	= is_pkvm_enabled,
 	}, {
-		.mask   = KVM_PGTABLE_PROT_SW1,
+		.mask	= KVM_PGTABLE_PROT_SW1,
 		.val	= KVM_PGTABLE_PROT_SW1,
-		.set	= "SW1", /* PKVM_PAGE_SHARED_BORROWED */
+		.set	= "SW1",
+		.feature_off	= is_pkvm_enabled,
 	}, {
-		.mask	= KVM_PGTABLE_PROT_SW2,
+		.mask   = KVM_PGTABLE_PROT_SW2,
 		.val	= KVM_PGTABLE_PROT_SW2,
 		.set	= "SW2",
+		.feature_off	= is_pkvm_enabled,
 	}, {
 		.mask   = KVM_PGTABLE_PROT_SW3,
 		.val	= KVM_PGTABLE_PROT_SW3,
 		.set	= "SW3",
+		.feature_off	= is_pkvm_enabled,
 	},
 };
 
-- 
2.43.0.472.g3155946c3a-goog




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