Merge branch kvm-arm64/6.6/misc into kvmarm-master/next

* kvm-arm64/6.6/misc:
  : .
  : Misc KVM/arm64 updates for 6.6:
  :
  : - Don't unnecessary align non-stack allocations in the EL2 VA space
  :
  : - Drop HCR_VIRT_EXCP_MASK, which was never used...
  :
  : - Don't use smp_processor_id() in kvm_arch_vcpu_load(),
  :   but the cpu parameter instead
  :
  : - Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort()
  :
  : - Remove prototypes without implementations
  : .
  KVM: arm64: Remove size-order align in the nVHE hyp private VA range
  KVM: arm64: Remove unused declarations
  KVM: arm64: Remove redundant kvm_set_pfn_accessed() from user_mem_abort()
  KVM: arm64: Drop HCR_VIRT_EXCP_MASK
  KVM: arm64: Use the known cpu id instead of smp_processor_id()

Signed-off-by: Marc Zyngier <maz@kernel.org>

3 files changed, 68 insertions, 43 deletions

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
index d5ec972b5c1e..230e4f2527de 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
@@ -26,6 +26,7 @@ int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot
 int __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
 				  enum kvm_pgtable_prot prot,
 				  unsigned long *haddr);
+int pkvm_create_stack(phys_addr_t phys, unsigned long *haddr);
 int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr);
 
 #endif /* __KVM_HYP_MM_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c
index 318298eb3d6b..65a7a186d7b2 100644
--- a/arch/arm64/kvm/hyp/nvhe/mm.c
+++ b/arch/arm64/kvm/hyp/nvhe/mm.c
@@ -44,6 +44,27 @@ static int __pkvm_create_mappings(unsigned long start, unsigned long size,
 	return err;
 }
 
+static int __pkvm_alloc_private_va_range(unsigned long start, size_t size)
+{
+	unsigned long cur;
+
+	hyp_assert_lock_held(&pkvm_pgd_lock);
+
+	if (!start || start < __io_map_base)
+		return -EINVAL;
+
+	/* The allocated size is always a multiple of PAGE_SIZE */
+	cur = start + PAGE_ALIGN(size);
+
+	/* Are we overflowing on the vmemmap ? */
+	if (cur > __hyp_vmemmap)
+		return -ENOMEM;
+
+	__io_map_base = cur;
+
+	return 0;
+}
+
 /**
  * pkvm_alloc_private_va_range - Allocates a private VA range.
  * @size:	The size of the VA range to reserve.
@@ -56,27 +77,16 @@ static int __pkvm_create_mappings(unsigned long start, unsigned long size,
  */
 int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr)
 {
-	unsigned long base, addr;
-	int ret = 0;
+	unsigned long addr;
+	int ret;
 
 	hyp_spin_lock(&pkvm_pgd_lock);
-
-	/* Align the allocation based on the order of its size */
-	addr = ALIGN(__io_map_base, PAGE_SIZE << get_order(size));
-
-	/* The allocated size is always a multiple of PAGE_SIZE */
-	base = addr + PAGE_ALIGN(size);
-
-	/* Are we overflowing on the vmemmap ? */
-	if (!addr || base > __hyp_vmemmap)
-		ret = -ENOMEM;
-	else {
-		__io_map_base = base;
-		*haddr = addr;
-	}
-
+	addr = __io_map_base;
+	ret = __pkvm_alloc_private_va_range(addr, size);
 	hyp_spin_unlock(&pkvm_pgd_lock);
 
+	*haddr = addr;
+
 	return ret;
 }
 
@@ -340,6 +350,45 @@ int hyp_create_idmap(u32 hyp_va_bits)
 	return __pkvm_create_mappings(start, end - start, start, PAGE_HYP_EXEC);
 }
 
+int pkvm_create_stack(phys_addr_t phys, unsigned long *haddr)
+{
+	unsigned long addr, prev_base;
+	size_t size;
+	int ret;
+
+	hyp_spin_lock(&pkvm_pgd_lock);
+
+	prev_base = __io_map_base;
+	/*
+	 * Efficient stack verification using the PAGE_SHIFT bit implies
+	 * an alignment of our allocation on the order of the size.
+	 */
+	size = PAGE_SIZE * 2;
+	addr = ALIGN(__io_map_base, size);
+
+	ret = __pkvm_alloc_private_va_range(addr, size);
+	if (!ret) {
+		/*
+		 * Since the stack grows downwards, map the stack to the page
+		 * at the higher address and leave the lower guard page
+		 * unbacked.
+		 *
+		 * Any valid stack address now has the PAGE_SHIFT bit as 1
+		 * and addresses corresponding to the guard page have the
+		 * PAGE_SHIFT bit as 0 - this is used for overflow detection.
+		 */
+		ret = kvm_pgtable_hyp_map(&pkvm_pgtable, addr + PAGE_SIZE,
+					  PAGE_SIZE, phys, PAGE_HYP);
+		if (ret)
+			__io_map_base = prev_base;
+	}
+	hyp_spin_unlock(&pkvm_pgd_lock);
+
+	*haddr = addr + size;
+
+	return ret;
+}
+
 static void *admit_host_page(void *arg)
 {
 	struct kvm_hyp_memcache *host_mc = arg;
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index bb98630dfeaf..0d5e0a89ddce 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -113,7 +113,6 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
 
 	for (i = 0; i < hyp_nr_cpus; i++) {
 		struct kvm_nvhe_init_params *params = per_cpu_ptr(&kvm_init_params, i);
-		unsigned long hyp_addr;
 
 		start = (void *)kern_hyp_va(per_cpu_base[i]);
 		end = start + PAGE_ALIGN(hyp_percpu_size);
@@ -121,33 +120,9 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
 		if (ret)
 			return ret;
 
-		/*
-		 * Allocate a contiguous HYP private VA range for the stack
-		 * and guard page. The allocation is also aligned based on
-		 * the order of its size.
-		 */
-		ret = pkvm_alloc_private_va_range(PAGE_SIZE * 2, &hyp_addr);
+		ret = pkvm_create_stack(params->stack_pa, &params->stack_hyp_va);
 		if (ret)
 			return ret;
-
-		/*
-		 * Since the stack grows downwards, map the stack to the page
-		 * at the higher address and leave the lower guard page
-		 * unbacked.
-		 *
-		 * Any valid stack address now has the PAGE_SHIFT bit as 1
-		 * and addresses corresponding to the guard page have the
-		 * PAGE_SHIFT bit as 0 - this is used for overflow detection.
-		 */
-		hyp_spin_lock(&pkvm_pgd_lock);
-		ret = kvm_pgtable_hyp_map(&pkvm_pgtable, hyp_addr + PAGE_SIZE,
-					PAGE_SIZE, params->stack_pa, PAGE_HYP);
-		hyp_spin_unlock(&pkvm_pgd_lock);
-		if (ret)
-			return ret;
-
-		/* Update stack_hyp_va to end of the stack's private VA range */
-		params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE);
 	}
 
 	/*