KVM: arm64: Introduce KVM_PGTABLE_S2_NOFWB stage 2 flag

In order to further configure stage 2 page-tables, pass flags to the
init function using a new enum.

The first of these flags allows to disable FWB even if the hardware
supports it as we will need to do so for the host stage 2.

Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210319100146.1149909-33-qperret@google.com

1 files changed, 29 insertions, 14 deletions

diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index e1fed14aee17..55452f4831d2 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -57,6 +57,15 @@ struct kvm_pgtable_mm_ops {
 };
 
 /**
+ * enum kvm_pgtable_stage2_flags - Stage-2 page-table flags.
+ * @KVM_PGTABLE_S2_NOFWB:	Don't enforce Normal-WB even if the CPUs have
+ *				ARM64_HAS_STAGE2_FWB.
+ */
+enum kvm_pgtable_stage2_flags {
+	KVM_PGTABLE_S2_NOFWB			= BIT(0),
+};
+
+/**
  * struct kvm_pgtable - KVM page-table.
  * @ia_bits:		Maximum input address size, in bits.
  * @start_level:	Level at which the page-table walk starts.
@@ -72,6 +81,7 @@ struct kvm_pgtable {
 
 	/* Stage-2 only */
 	struct kvm_s2_mmu			*mmu;
+	enum kvm_pgtable_stage2_flags		flags;
 };
 
 /**
@@ -196,20 +206,25 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
 u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift);
 
 /**
- * kvm_pgtable_stage2_init() - Initialise a guest stage-2 page-table.
+ * kvm_pgtable_stage2_init_flags() - Initialise a guest stage-2 page-table.
  * @pgt:	Uninitialised page-table structure to initialise.
  * @arch:	Arch-specific KVM structure representing the guest virtual
  *		machine.
  * @mm_ops:	Memory management callbacks.
+ * @flags:	Stage-2 configuration flags.
  *
  * Return: 0 on success, negative error code on failure.
  */
-int kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_arch *arch,
-			    struct kvm_pgtable_mm_ops *mm_ops);
+int kvm_pgtable_stage2_init_flags(struct kvm_pgtable *pgt, struct kvm_arch *arch,
+				  struct kvm_pgtable_mm_ops *mm_ops,
+				  enum kvm_pgtable_stage2_flags flags);
+
+#define kvm_pgtable_stage2_init(pgt, arch, mm_ops) \
+	kvm_pgtable_stage2_init_flags(pgt, arch, mm_ops, 0)
 
 /**
  * kvm_pgtable_stage2_destroy() - Destroy an unused guest stage-2 page-table.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  *
  * The page-table is assumed to be unreachable by any hardware walkers prior
  * to freeing and therefore no TLB invalidation is performed.
@@ -218,7 +233,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt);
 
 /**
  * kvm_pgtable_stage2_map() - Install a mapping in a guest stage-2 page-table.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address at which to place the mapping.
  * @size:	Size of the mapping.
  * @phys:	Physical address of the memory to map.
@@ -251,7 +266,7 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
 /**
  * kvm_pgtable_stage2_set_owner() - Unmap and annotate pages in the IPA space to
  *				    track ownership.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Base intermediate physical address to annotate.
  * @size:	Size of the annotated range.
  * @mc:		Cache of pre-allocated and zeroed memory from which to allocate
@@ -270,7 +285,7 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
 
 /**
  * kvm_pgtable_stage2_unmap() - Remove a mapping from a guest stage-2 page-table.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address from which to remove the mapping.
  * @size:	Size of the mapping.
  *
@@ -290,7 +305,7 @@ int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);
 /**
  * kvm_pgtable_stage2_wrprotect() - Write-protect guest stage-2 address range
  *                                  without TLB invalidation.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address from which to write-protect,
  * @size:	Size of the range.
  *
@@ -307,7 +322,7 @@ int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size);
 
 /**
  * kvm_pgtable_stage2_mkyoung() - Set the access flag in a page-table entry.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address to identify the page-table entry.
  *
  * The offset of @addr within a page is ignored.
@@ -321,7 +336,7 @@ kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr);
 
 /**
  * kvm_pgtable_stage2_mkold() - Clear the access flag in a page-table entry.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address to identify the page-table entry.
  *
  * The offset of @addr within a page is ignored.
@@ -340,7 +355,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr);
 /**
  * kvm_pgtable_stage2_relax_perms() - Relax the permissions enforced by a
  *				      page-table entry.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address to identify the page-table entry.
  * @prot:	Additional permissions to grant for the mapping.
  *
@@ -359,7 +374,7 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
 /**
  * kvm_pgtable_stage2_is_young() - Test whether a page-table entry has the
  *				   access flag set.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address to identify the page-table entry.
  *
  * The offset of @addr within a page is ignored.
@@ -372,7 +387,7 @@ bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr);
  * kvm_pgtable_stage2_flush_range() - Clean and invalidate data cache to Point
  * 				      of Coherency for guest stage-2 address
  *				      range.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address from which to flush.
  * @size:	Size of the range.
  *
@@ -411,7 +426,7 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
  * kvm_pgtable_stage2_find_range() - Find a range of Intermediate Physical
  *				     Addresses with compatible permission
  *				     attributes.
- * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init().
+ * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Address that must be covered by the range.
  * @prot:	Protection attributes that the range must be compatible with.
  * @range:	Range structure used to limit the search space at call time and