[PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Kalesh Singh]

Hi all,

This is v8 of the nVHE hypervisor stack enhancements. This version is based
on 5.18-rc3.

Previous versions can be found at: 
v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/

Thanks,
Kalesh

-----

This series is based on 5.18-rc3 and adds stack guard pages to nVHE and pKVM
hypervisor; and symbolization of hypervisor addresses.

The guard page stack overflow detection is based on the technique used by
arm64 VMAP_STACK. i.e. the stack is aligned such that the 'stack shift' bit 
of any valid SP is 1. The 'stack shift' bit can be tested in the exception
entry to detect overflow without corrupting GPRs.


Kalesh Singh (6):
  KVM: arm64: Introduce hyp_alloc_private_va_range()
  KVM: arm64: Introduce pkvm_alloc_private_va_range()
  KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
  KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
  KVM: arm64: Detect and handle hypervisor stack overflows
  KVM: arm64: Symbolize the nVHE HYP addresses

 arch/arm64/include/asm/kvm_asm.h     |  1 +
 arch/arm64/include/asm/kvm_mmu.h     |  3 ++
 arch/arm64/kvm/arm.c                 | 37 +++++++++++--
 arch/arm64/kvm/handle_exit.c         | 13 ++---
 arch/arm64/kvm/hyp/include/nvhe/mm.h |  6 ++-
 arch/arm64/kvm/hyp/nvhe/host.S       | 24 +++++++++
 arch/arm64/kvm/hyp/nvhe/hyp-main.c   | 18 ++++++-
 arch/arm64/kvm/hyp/nvhe/mm.c         | 78 ++++++++++++++++++----------
 arch/arm64/kvm/hyp/nvhe/setup.c      | 31 +++++++++--
 arch/arm64/kvm/hyp/nvhe/switch.c     |  7 ++-
 arch/arm64/kvm/mmu.c                 | 68 ++++++++++++++++--------
 scripts/kallsyms.c                   |  3 +-
 12 files changed, 220 insertions(+), 69 deletions(-)


base-commit: b2d229d4ddb17db541098b83524d901257e93845
-- 
2.36.0.rc0.470.gd361397f0d-goog

[PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Kalesh Singh]

Hi all,

This is v8 of the nVHE hypervisor stack enhancements. This version is based
on 5.18-rc3.

Previous versions can be found at: 
v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/

Thanks,
Kalesh

-----

This series is based on 5.18-rc3 and adds stack guard pages to nVHE and pKVM
hypervisor; and symbolization of hypervisor addresses.

The guard page stack overflow detection is based on the technique used by
arm64 VMAP_STACK. i.e. the stack is aligned such that the 'stack shift' bit 
of any valid SP is 1. The 'stack shift' bit can be tested in the exception
entry to detect overflow without corrupting GPRs.


Kalesh Singh (6):
  KVM: arm64: Introduce hyp_alloc_private_va_range()
  KVM: arm64: Introduce pkvm_alloc_private_va_range()
  KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
  KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
  KVM: arm64: Detect and handle hypervisor stack overflows
  KVM: arm64: Symbolize the nVHE HYP addresses

 arch/arm64/include/asm/kvm_asm.h     |  1 +
 arch/arm64/include/asm/kvm_mmu.h     |  3 ++
 arch/arm64/kvm/arm.c                 | 37 +++++++++++--
 arch/arm64/kvm/handle_exit.c         | 13 ++---
 arch/arm64/kvm/hyp/include/nvhe/mm.h |  6 ++-
 arch/arm64/kvm/hyp/nvhe/host.S       | 24 +++++++++
 arch/arm64/kvm/hyp/nvhe/hyp-main.c   | 18 ++++++-
 arch/arm64/kvm/hyp/nvhe/mm.c         | 78 ++++++++++++++++++----------
 arch/arm64/kvm/hyp/nvhe/setup.c      | 31 +++++++++--
 arch/arm64/kvm/hyp/nvhe/switch.c     |  7 ++-
 arch/arm64/kvm/mmu.c                 | 68 ++++++++++++++++--------
 scripts/kallsyms.c                   |  3 +-
 12 files changed, 220 insertions(+), 69 deletions(-)


base-commit: b2d229d4ddb17db541098b83524d901257e93845
-- 
2.36.0.rc0.470.gd361397f0d-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Kalesh Singh]

Hi all,

This is v8 of the nVHE hypervisor stack enhancements. This version is based
on 5.18-rc3.

Previous versions can be found at: 
v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/

Thanks,
Kalesh

-----

This series is based on 5.18-rc3 and adds stack guard pages to nVHE and pKVM
hypervisor; and symbolization of hypervisor addresses.

The guard page stack overflow detection is based on the technique used by
arm64 VMAP_STACK. i.e. the stack is aligned such that the 'stack shift' bit 
of any valid SP is 1. The 'stack shift' bit can be tested in the exception
entry to detect overflow without corrupting GPRs.


Kalesh Singh (6):
  KVM: arm64: Introduce hyp_alloc_private_va_range()
  KVM: arm64: Introduce pkvm_alloc_private_va_range()
  KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
  KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
  KVM: arm64: Detect and handle hypervisor stack overflows
  KVM: arm64: Symbolize the nVHE HYP addresses

 arch/arm64/include/asm/kvm_asm.h     |  1 +
 arch/arm64/include/asm/kvm_mmu.h     |  3 ++
 arch/arm64/kvm/arm.c                 | 37 +++++++++++--
 arch/arm64/kvm/handle_exit.c         | 13 ++---
 arch/arm64/kvm/hyp/include/nvhe/mm.h |  6 ++-
 arch/arm64/kvm/hyp/nvhe/host.S       | 24 +++++++++
 arch/arm64/kvm/hyp/nvhe/hyp-main.c   | 18 ++++++-
 arch/arm64/kvm/hyp/nvhe/mm.c         | 78 ++++++++++++++++++----------
 arch/arm64/kvm/hyp/nvhe/setup.c      | 31 +++++++++--
 arch/arm64/kvm/hyp/nvhe/switch.c     |  7 ++-
 arch/arm64/kvm/mmu.c                 | 68 ++++++++++++++++--------
 scripts/kallsyms.c                   |  3 +-
 12 files changed, 220 insertions(+), 69 deletions(-)


base-commit: b2d229d4ddb17db541098b83524d901257e93845
-- 
2.36.0.rc0.470.gd361397f0d-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v8 1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()

[Kalesh Singh]

hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the nVHE hypervisor. Allocations are aligned based on the order of
the requested size.

This will be used to implement stack guard pages for KVM nVHE hypervisor
(nVHE Hyp mode / not pKVM), in a subsequent patch in the series.

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8
  - Remove !base check in hyp_alloc_private_va_range(), per Marc
  - PAGE_ALIGN the size in __create_hyp_private_mapping(), per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update kernel-doc for hyp_alloc_private_va_range()
    and add return description, per Stephen
  - Update hyp_alloc_private_va_range() to return an int error code,
    per Stephen
  - Replace IS_ERR() checks with IS_ERR_VALUE() check, per Stephen
  - Clean up goto, per Stephen

Changes in v5:
  - Align private allocations based on the order of their size, per Marc

Changes in v4:
  - Handle null ptr in hyp_alloc_private_va_range() and replace
    IS_ERR_OR_NULL checks in callers with IS_ERR checks, per Fuad
  - Fix kernel-doc comments format, per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark


 arch/arm64/include/asm/kvm_mmu.h |  1 +
 arch/arm64/kvm/mmu.c             | 64 +++++++++++++++++++++-----------
 2 files changed, 44 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 74735a864eee..a50cbb5ba402 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -154,6 +154,7 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v)
 int kvm_share_hyp(void *from, void *to);
 void kvm_unshare_hyp(void *from, void *to);
 int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
+int hyp_alloc_private_va_range(size_t size, unsigned long *haddr);
 int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 			   void __iomem **kaddr,
 			   void __iomem **haddr);
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 53ae2c0640bc..7de1e02ebfd1 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -457,23 +457,22 @@ int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
 	return 0;
 }
 
-static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
-					unsigned long *haddr,
-					enum kvm_pgtable_prot prot)
+
+/**
+ * hyp_alloc_private_va_range - Allocates a private VA range.
+ * @size:	The size of the VA range to reserve.
+ * @haddr:	The hypervisor virtual start address of the allocation.
+ *
+ * The private virtual address (VA) range is allocated below io_map_base
+ * and aligned based on the order of @size.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int hyp_alloc_private_va_range(size_t size, unsigned long *haddr)
 {
 	unsigned long base;
 	int ret = 0;
 
-	if (!kvm_host_owns_hyp_mappings()) {
-		base = kvm_call_hyp_nvhe(__pkvm_create_private_mapping,
-					 phys_addr, size, prot);
-		if (IS_ERR_OR_NULL((void *)base))
-			return PTR_ERR((void *)base);
-		*haddr = base;
-
-		return 0;
-	}
-
 	mutex_lock(&kvm_hyp_pgd_mutex);
 
 	/*
@@ -484,8 +483,10 @@ static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
 	 *
 	 * The allocated size is always a multiple of PAGE_SIZE.
 	 */
-	size = PAGE_ALIGN(size + offset_in_page(phys_addr));
-	base = io_map_base - size;
+	base = io_map_base - PAGE_ALIGN(size);
+
+	/* Align the allocation based on the order of its size */
+	base = ALIGN_DOWN(base, PAGE_SIZE << get_order(size));
 
 	/*
 	 * Verify that BIT(VA_BITS - 1) hasn't been flipped by
@@ -495,19 +496,40 @@ static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
 	if ((base ^ io_map_base) & BIT(VA_BITS - 1))
 		ret = -ENOMEM;
 	else
-		io_map_base = base;
+		*haddr = io_map_base = base;
 
 	mutex_unlock(&kvm_hyp_pgd_mutex);
 
+	return ret;
+}
+
+static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
+					unsigned long *haddr,
+					enum kvm_pgtable_prot prot)
+{
+	unsigned long addr;
+	int ret = 0;
+
+	if (!kvm_host_owns_hyp_mappings()) {
+		addr = kvm_call_hyp_nvhe(__pkvm_create_private_mapping,
+					 phys_addr, size, prot);
+		if (IS_ERR_VALUE(addr))
+			return addr;
+		*haddr = addr;
+
+		return 0;
+	}
+
+	size = PAGE_ALIGN(size + offset_in_page(phys_addr));
+	ret = hyp_alloc_private_va_range(size, &addr);
 	if (ret)
-		goto out;
+		return ret;
 
-	ret = __create_hyp_mappings(base, size, phys_addr, prot);
+	ret = __create_hyp_mappings(addr, size, phys_addr, prot);
 	if (ret)
-		goto out;
+		return ret;
 
-	*haddr = base + offset_in_page(phys_addr);
-out:
+	*haddr = addr + offset_in_page(phys_addr);
 	return ret;
 }
 
-- 
2.36.0.rc0.470.gd361397f0d-goog

[PATCH v8 1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()

[Kalesh Singh]

hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the nVHE hypervisor. Allocations are aligned based on the order of
the requested size.

This will be used to implement stack guard pages for KVM nVHE hypervisor
(nVHE Hyp mode / not pKVM), in a subsequent patch in the series.

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8
  - Remove !base check in hyp_alloc_private_va_range(), per Marc
  - PAGE_ALIGN the size in __create_hyp_private_mapping(), per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update kernel-doc for hyp_alloc_private_va_range()
    and add return description, per Stephen
  - Update hyp_alloc_private_va_range() to return an int error code,
    per Stephen
  - Replace IS_ERR() checks with IS_ERR_VALUE() check, per Stephen
  - Clean up goto, per Stephen

Changes in v5:
  - Align private allocations based on the order of their size, per Marc

Changes in v4:
  - Handle null ptr in hyp_alloc_private_va_range() and replace
    IS_ERR_OR_NULL checks in callers with IS_ERR checks, per Fuad
  - Fix kernel-doc comments format, per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark


 arch/arm64/include/asm/kvm_mmu.h |  1 +
 arch/arm64/kvm/mmu.c             | 64 +++++++++++++++++++++-----------
 2 files changed, 44 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 74735a864eee..a50cbb5ba402 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -154,6 +154,7 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v)
 int kvm_share_hyp(void *from, void *to);
 void kvm_unshare_hyp(void *from, void *to);
 int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
+int hyp_alloc_private_va_range(size_t size, unsigned long *haddr);
 int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 			   void __iomem **kaddr,
 			   void __iomem **haddr);
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 53ae2c0640bc..7de1e02ebfd1 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -457,23 +457,22 @@ int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
 	return 0;
 }
 
-static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
-					unsigned long *haddr,
-					enum kvm_pgtable_prot prot)
+
+/**
+ * hyp_alloc_private_va_range - Allocates a private VA range.
+ * @size:	The size of the VA range to reserve.
+ * @haddr:	The hypervisor virtual start address of the allocation.
+ *
+ * The private virtual address (VA) range is allocated below io_map_base
+ * and aligned based on the order of @size.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int hyp_alloc_private_va_range(size_t size, unsigned long *haddr)
 {
 	unsigned long base;
 	int ret = 0;
 
-	if (!kvm_host_owns_hyp_mappings()) {
-		base = kvm_call_hyp_nvhe(__pkvm_create_private_mapping,
-					 phys_addr, size, prot);
-		if (IS_ERR_OR_NULL((void *)base))
-			return PTR_ERR((void *)base);
-		*haddr = base;
-
-		return 0;
-	}
-
 	mutex_lock(&kvm_hyp_pgd_mutex);
 
 	/*
@@ -484,8 +483,10 @@ static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
 	 *
 	 * The allocated size is always a multiple of PAGE_SIZE.
 	 */
-	size = PAGE_ALIGN(size + offset_in_page(phys_addr));
-	base = io_map_base - size;
+	base = io_map_base - PAGE_ALIGN(size);
+
+	/* Align the allocation based on the order of its size */
+	base = ALIGN_DOWN(base, PAGE_SIZE << get_order(size));
 
 	/*
 	 * Verify that BIT(VA_BITS - 1) hasn't been flipped by
@@ -495,19 +496,40 @@ static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
 	if ((base ^ io_map_base) & BIT(VA_BITS - 1))
 		ret = -ENOMEM;
 	else
-		io_map_base = base;
+		*haddr = io_map_base = base;
 
 	mutex_unlock(&kvm_hyp_pgd_mutex);
 
+	return ret;
+}
+
+static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
+					unsigned long *haddr,
+					enum kvm_pgtable_prot prot)
+{
+	unsigned long addr;
+	int ret = 0;
+
+	if (!kvm_host_owns_hyp_mappings()) {
+		addr = kvm_call_hyp_nvhe(__pkvm_create_private_mapping,
+					 phys_addr, size, prot);
+		if (IS_ERR_VALUE(addr))
+			return addr;
+		*haddr = addr;
+
+		return 0;
+	}
+
+	size = PAGE_ALIGN(size + offset_in_page(phys_addr));
+	ret = hyp_alloc_private_va_range(size, &addr);
 	if (ret)
-		goto out;
+		return ret;
 
-	ret = __create_hyp_mappings(base, size, phys_addr, prot);
+	ret = __create_hyp_mappings(addr, size, phys_addr, prot);
 	if (ret)
-		goto out;
+		return ret;
 
-	*haddr = base + offset_in_page(phys_addr);
-out:
+	*haddr = addr + offset_in_page(phys_addr);
 	return ret;
 }
 
-- 
2.36.0.rc0.470.gd361397f0d-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v8 1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()

[Kalesh Singh]

hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the nVHE hypervisor. Allocations are aligned based on the order of
the requested size.

This will be used to implement stack guard pages for KVM nVHE hypervisor
(nVHE Hyp mode / not pKVM), in a subsequent patch in the series.

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8
  - Remove !base check in hyp_alloc_private_va_range(), per Marc
  - PAGE_ALIGN the size in __create_hyp_private_mapping(), per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update kernel-doc for hyp_alloc_private_va_range()
    and add return description, per Stephen
  - Update hyp_alloc_private_va_range() to return an int error code,
    per Stephen
  - Replace IS_ERR() checks with IS_ERR_VALUE() check, per Stephen
  - Clean up goto, per Stephen

Changes in v5:
  - Align private allocations based on the order of their size, per Marc

Changes in v4:
  - Handle null ptr in hyp_alloc_private_va_range() and replace
    IS_ERR_OR_NULL checks in callers with IS_ERR checks, per Fuad
  - Fix kernel-doc comments format, per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark


 arch/arm64/include/asm/kvm_mmu.h |  1 +
 arch/arm64/kvm/mmu.c             | 64 +++++++++++++++++++++-----------
 2 files changed, 44 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 74735a864eee..a50cbb5ba402 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -154,6 +154,7 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v)
 int kvm_share_hyp(void *from, void *to);
 void kvm_unshare_hyp(void *from, void *to);
 int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
+int hyp_alloc_private_va_range(size_t size, unsigned long *haddr);
 int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 			   void __iomem **kaddr,
 			   void __iomem **haddr);
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 53ae2c0640bc..7de1e02ebfd1 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -457,23 +457,22 @@ int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
 	return 0;
 }
 
-static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
-					unsigned long *haddr,
-					enum kvm_pgtable_prot prot)
+
+/**
+ * hyp_alloc_private_va_range - Allocates a private VA range.
+ * @size:	The size of the VA range to reserve.
+ * @haddr:	The hypervisor virtual start address of the allocation.
+ *
+ * The private virtual address (VA) range is allocated below io_map_base
+ * and aligned based on the order of @size.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int hyp_alloc_private_va_range(size_t size, unsigned long *haddr)
 {
 	unsigned long base;
 	int ret = 0;
 
-	if (!kvm_host_owns_hyp_mappings()) {
-		base = kvm_call_hyp_nvhe(__pkvm_create_private_mapping,
-					 phys_addr, size, prot);
-		if (IS_ERR_OR_NULL((void *)base))
-			return PTR_ERR((void *)base);
-		*haddr = base;
-
-		return 0;
-	}
-
 	mutex_lock(&kvm_hyp_pgd_mutex);
 
 	/*
@@ -484,8 +483,10 @@ static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
 	 *
 	 * The allocated size is always a multiple of PAGE_SIZE.
 	 */
-	size = PAGE_ALIGN(size + offset_in_page(phys_addr));
-	base = io_map_base - size;
+	base = io_map_base - PAGE_ALIGN(size);
+
+	/* Align the allocation based on the order of its size */
+	base = ALIGN_DOWN(base, PAGE_SIZE << get_order(size));
 
 	/*
 	 * Verify that BIT(VA_BITS - 1) hasn't been flipped by
@@ -495,19 +496,40 @@ static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
 	if ((base ^ io_map_base) & BIT(VA_BITS - 1))
 		ret = -ENOMEM;
 	else
-		io_map_base = base;
+		*haddr = io_map_base = base;
 
 	mutex_unlock(&kvm_hyp_pgd_mutex);
 
+	return ret;
+}
+
+static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
+					unsigned long *haddr,
+					enum kvm_pgtable_prot prot)
+{
+	unsigned long addr;
+	int ret = 0;
+
+	if (!kvm_host_owns_hyp_mappings()) {
+		addr = kvm_call_hyp_nvhe(__pkvm_create_private_mapping,
+					 phys_addr, size, prot);
+		if (IS_ERR_VALUE(addr))
+			return addr;
+		*haddr = addr;
+
+		return 0;
+	}
+
+	size = PAGE_ALIGN(size + offset_in_page(phys_addr));
+	ret = hyp_alloc_private_va_range(size, &addr);
 	if (ret)
-		goto out;
+		return ret;
 
-	ret = __create_hyp_mappings(base, size, phys_addr, prot);
+	ret = __create_hyp_mappings(addr, size, phys_addr, prot);
 	if (ret)
-		goto out;
+		return ret;
 
-	*haddr = base + offset_in_page(phys_addr);
-out:
+	*haddr = addr + offset_in_page(phys_addr);
 	return ret;
 }
 
-- 
2.36.0.rc0.470.gd361397f0d-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v8 2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()

[Kalesh Singh]

pkvm_hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the pKVM nVHE hypervisor. Allocations are aligned based on the order of
the requested size.

This will be used to implement stack guard pages for pKVM nVHE hypervisor
(in a subsequent patch in the series).

Credits to Quentin Perret <qperret@google.com> for the idea of moving
private VA allocation out of __pkvm_create_private_mapping()

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - PAGE_ALIGN the size in __pkvm_create_private_mapping(), per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update kernel-doc for pkvm_alloc_private_va_range() and add
    return description, per Stephen
  - Update pkvm_alloc_private_va_range() to return an int error code,
    per Stephen
  - Update __pkvm_create_private_mapping to return an in error code,
    per Quentin
  - Update callers of __pkvm_create_private_mapping() to handle new
    return value and params.

Changes in v5:
  - Align private allocations based on the order of their size, per Marc

Changes in v4:
  - Handle null ptr in pkvm_alloc_private_va_range() and replace
    IS_ERR_OR_NULL checks in callers with IS_ERR checks, per Fuad
  - Fix kernel-doc comments format, per Fuad
  - Format __pkvm_create_private_mapping() prototype args (< 80 col), per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark

Changes in v2:
  - Allow specifying an alignment for the private VA allocations, per Marc


 arch/arm64/kvm/hyp/include/nvhe/mm.h |  6 ++-
 arch/arm64/kvm/hyp/nvhe/hyp-main.c   | 18 ++++++-
 arch/arm64/kvm/hyp/nvhe/mm.c         | 78 ++++++++++++++++++----------
 3 files changed, 72 insertions(+), 30 deletions(-)

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
index 2d08510c6cc1..42d8eb9bfe72 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
@@ -19,8 +19,10 @@ int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back);
 int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot);
 int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
 int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot);
-unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
-					    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_alloc_private_va_range(size_t size, unsigned long *haddr);
 
 static inline void hyp_vmemmap_range(phys_addr_t phys, unsigned long size,
 				     unsigned long *start, unsigned long *end)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 5e2197db0d32..3cea4b6ac23e 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -160,7 +160,23 @@ static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ct
 	DECLARE_REG(size_t, size, host_ctxt, 2);
 	DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3);
 
-	cpu_reg(host_ctxt, 1) = __pkvm_create_private_mapping(phys, size, prot);
+	/*
+	 * __pkvm_create_private_mapping() populates a pointer with the
+	 * hypervisor start address of the allocation.
+	 *
+	 * However, handle___pkvm_create_private_mapping() hypercall crosses the
+	 * EL1/EL2 boundary so the pointer would not be valid in this context.
+	 *
+	 * Instead pass the allocation address as the return value (or return
+	 * ERR_PTR() on failure).
+	 */
+	unsigned long haddr;
+	int err = __pkvm_create_private_mapping(phys, size, prot, &haddr);
+
+	if (err)
+		haddr = (unsigned long)ERR_PTR(err);
+
+	cpu_reg(host_ctxt, 1) = haddr;
 }
 
 static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c
index cdbe8e246418..96193cb31a39 100644
--- a/arch/arm64/kvm/hyp/nvhe/mm.c
+++ b/arch/arm64/kvm/hyp/nvhe/mm.c
@@ -37,36 +37,60 @@ static int __pkvm_create_mappings(unsigned long start, unsigned long size,
 	return err;
 }
 
-unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
-					    enum kvm_pgtable_prot prot)
+/**
+ * pkvm_alloc_private_va_range - Allocates a private VA range.
+ * @size:	The size of the VA range to reserve.
+ * @haddr:	The hypervisor virtual start address of the allocation.
+ *
+ * The private virtual address (VA) range is allocated above __io_map_base
+ * and aligned based on the order of @size.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr)
 {
-	unsigned long addr;
-	int err;
+	unsigned long base, addr;
+	int ret = 0;
 
 	hyp_spin_lock(&pkvm_pgd_lock);
 
-	size = PAGE_ALIGN(size + offset_in_page(phys));
-	addr = __io_map_base;
-	__io_map_base += size;
+	/* Align the allocation based on the order of its size */
+	addr = ALIGN(__io_map_base, PAGE_SIZE << get_order(size));
 
-	/* Are we overflowing on the vmemmap ? */
-	if (__io_map_base > __hyp_vmemmap) {
-		__io_map_base -= size;
-		addr = (unsigned long)ERR_PTR(-ENOMEM);
-		goto out;
-	}
+	/* The allocated size is always a multiple of PAGE_SIZE */
+	base = addr + PAGE_ALIGN(size);
 
-	err = kvm_pgtable_hyp_map(&pkvm_pgtable, addr, size, phys, prot);
-	if (err) {
-		addr = (unsigned long)ERR_PTR(err);
-		goto out;
+	/* Are we overflowing on the vmemmap ? */
+	if (!addr || base > __hyp_vmemmap)
+		ret = -ENOMEM;
+	else {
+		__io_map_base = base;
+		*haddr = addr;
 	}
 
-	addr = addr + offset_in_page(phys);
-out:
 	hyp_spin_unlock(&pkvm_pgd_lock);
 
-	return addr;
+	return ret;
+}
+
+int __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
+				  enum kvm_pgtable_prot prot,
+				  unsigned long *haddr)
+{
+	unsigned long addr;
+	int err;
+
+	size = PAGE_ALIGN(size + offset_in_page(phys));
+	err = pkvm_alloc_private_va_range(size, &addr);
+	if (err)
+		return err;
+
+	err = __pkvm_create_mappings(addr, size, phys, prot);
+	if (err)
+		return err;
+
+	*haddr = addr + offset_in_page(phys);
+	return err;
 }
 
 int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot)
@@ -146,7 +170,8 @@ int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot)
 int hyp_map_vectors(void)
 {
 	phys_addr_t phys;
-	void *bp_base;
+	unsigned long bp_base;
+	int ret;
 
 	if (!kvm_system_needs_idmapped_vectors()) {
 		__hyp_bp_vect_base = __bp_harden_hyp_vecs;
@@ -154,13 +179,12 @@ int hyp_map_vectors(void)
 	}
 
 	phys = __hyp_pa(__bp_harden_hyp_vecs);
-	bp_base = (void *)__pkvm_create_private_mapping(phys,
-							__BP_HARDEN_HYP_VECS_SZ,
-							PAGE_HYP_EXEC);
-	if (IS_ERR_OR_NULL(bp_base))
-		return PTR_ERR(bp_base);
+	ret = __pkvm_create_private_mapping(phys, __BP_HARDEN_HYP_VECS_SZ,
+					    PAGE_HYP_EXEC, &bp_base);
+	if (ret)
+		return ret;
 
-	__hyp_bp_vect_base = bp_base;
+	__hyp_bp_vect_base = (void *)bp_base;
 
 	return 0;
 }
-- 
2.36.0.rc0.470.gd361397f0d-goog

[PATCH v8 2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()

[Kalesh Singh]

pkvm_hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the pKVM nVHE hypervisor. Allocations are aligned based on the order of
the requested size.

This will be used to implement stack guard pages for pKVM nVHE hypervisor
(in a subsequent patch in the series).

Credits to Quentin Perret <qperret@google.com> for the idea of moving
private VA allocation out of __pkvm_create_private_mapping()

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - PAGE_ALIGN the size in __pkvm_create_private_mapping(), per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update kernel-doc for pkvm_alloc_private_va_range() and add
    return description, per Stephen
  - Update pkvm_alloc_private_va_range() to return an int error code,
    per Stephen
  - Update __pkvm_create_private_mapping to return an in error code,
    per Quentin
  - Update callers of __pkvm_create_private_mapping() to handle new
    return value and params.

Changes in v5:
  - Align private allocations based on the order of their size, per Marc

Changes in v4:
  - Handle null ptr in pkvm_alloc_private_va_range() and replace
    IS_ERR_OR_NULL checks in callers with IS_ERR checks, per Fuad
  - Fix kernel-doc comments format, per Fuad
  - Format __pkvm_create_private_mapping() prototype args (< 80 col), per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark

Changes in v2:
  - Allow specifying an alignment for the private VA allocations, per Marc


 arch/arm64/kvm/hyp/include/nvhe/mm.h |  6 ++-
 arch/arm64/kvm/hyp/nvhe/hyp-main.c   | 18 ++++++-
 arch/arm64/kvm/hyp/nvhe/mm.c         | 78 ++++++++++++++++++----------
 3 files changed, 72 insertions(+), 30 deletions(-)

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
index 2d08510c6cc1..42d8eb9bfe72 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
@@ -19,8 +19,10 @@ int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back);
 int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot);
 int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
 int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot);
-unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
-					    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_alloc_private_va_range(size_t size, unsigned long *haddr);
 
 static inline void hyp_vmemmap_range(phys_addr_t phys, unsigned long size,
 				     unsigned long *start, unsigned long *end)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 5e2197db0d32..3cea4b6ac23e 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -160,7 +160,23 @@ static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ct
 	DECLARE_REG(size_t, size, host_ctxt, 2);
 	DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3);
 
-	cpu_reg(host_ctxt, 1) = __pkvm_create_private_mapping(phys, size, prot);
+	/*
+	 * __pkvm_create_private_mapping() populates a pointer with the
+	 * hypervisor start address of the allocation.
+	 *
+	 * However, handle___pkvm_create_private_mapping() hypercall crosses the
+	 * EL1/EL2 boundary so the pointer would not be valid in this context.
+	 *
+	 * Instead pass the allocation address as the return value (or return
+	 * ERR_PTR() on failure).
+	 */
+	unsigned long haddr;
+	int err = __pkvm_create_private_mapping(phys, size, prot, &haddr);
+
+	if (err)
+		haddr = (unsigned long)ERR_PTR(err);
+
+	cpu_reg(host_ctxt, 1) = haddr;
 }
 
 static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c
index cdbe8e246418..96193cb31a39 100644
--- a/arch/arm64/kvm/hyp/nvhe/mm.c
+++ b/arch/arm64/kvm/hyp/nvhe/mm.c
@@ -37,36 +37,60 @@ static int __pkvm_create_mappings(unsigned long start, unsigned long size,
 	return err;
 }
 
-unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
-					    enum kvm_pgtable_prot prot)
+/**
+ * pkvm_alloc_private_va_range - Allocates a private VA range.
+ * @size:	The size of the VA range to reserve.
+ * @haddr:	The hypervisor virtual start address of the allocation.
+ *
+ * The private virtual address (VA) range is allocated above __io_map_base
+ * and aligned based on the order of @size.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr)
 {
-	unsigned long addr;
-	int err;
+	unsigned long base, addr;
+	int ret = 0;
 
 	hyp_spin_lock(&pkvm_pgd_lock);
 
-	size = PAGE_ALIGN(size + offset_in_page(phys));
-	addr = __io_map_base;
-	__io_map_base += size;
+	/* Align the allocation based on the order of its size */
+	addr = ALIGN(__io_map_base, PAGE_SIZE << get_order(size));
 
-	/* Are we overflowing on the vmemmap ? */
-	if (__io_map_base > __hyp_vmemmap) {
-		__io_map_base -= size;
-		addr = (unsigned long)ERR_PTR(-ENOMEM);
-		goto out;
-	}
+	/* The allocated size is always a multiple of PAGE_SIZE */
+	base = addr + PAGE_ALIGN(size);
 
-	err = kvm_pgtable_hyp_map(&pkvm_pgtable, addr, size, phys, prot);
-	if (err) {
-		addr = (unsigned long)ERR_PTR(err);
-		goto out;
+	/* Are we overflowing on the vmemmap ? */
+	if (!addr || base > __hyp_vmemmap)
+		ret = -ENOMEM;
+	else {
+		__io_map_base = base;
+		*haddr = addr;
 	}
 
-	addr = addr + offset_in_page(phys);
-out:
 	hyp_spin_unlock(&pkvm_pgd_lock);
 
-	return addr;
+	return ret;
+}
+
+int __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
+				  enum kvm_pgtable_prot prot,
+				  unsigned long *haddr)
+{
+	unsigned long addr;
+	int err;
+
+	size = PAGE_ALIGN(size + offset_in_page(phys));
+	err = pkvm_alloc_private_va_range(size, &addr);
+	if (err)
+		return err;
+
+	err = __pkvm_create_mappings(addr, size, phys, prot);
+	if (err)
+		return err;
+
+	*haddr = addr + offset_in_page(phys);
+	return err;
 }
 
 int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot)
@@ -146,7 +170,8 @@ int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot)
 int hyp_map_vectors(void)
 {
 	phys_addr_t phys;
-	void *bp_base;
+	unsigned long bp_base;
+	int ret;
 
 	if (!kvm_system_needs_idmapped_vectors()) {
 		__hyp_bp_vect_base = __bp_harden_hyp_vecs;
@@ -154,13 +179,12 @@ int hyp_map_vectors(void)
 	}
 
 	phys = __hyp_pa(__bp_harden_hyp_vecs);
-	bp_base = (void *)__pkvm_create_private_mapping(phys,
-							__BP_HARDEN_HYP_VECS_SZ,
-							PAGE_HYP_EXEC);
-	if (IS_ERR_OR_NULL(bp_base))
-		return PTR_ERR(bp_base);
+	ret = __pkvm_create_private_mapping(phys, __BP_HARDEN_HYP_VECS_SZ,
+					    PAGE_HYP_EXEC, &bp_base);
+	if (ret)
+		return ret;
 
-	__hyp_bp_vect_base = bp_base;
+	__hyp_bp_vect_base = (void *)bp_base;
 
 	return 0;
 }
-- 
2.36.0.rc0.470.gd361397f0d-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v8 2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()

[Kalesh Singh]

pkvm_hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the pKVM nVHE hypervisor. Allocations are aligned based on the order of
the requested size.

This will be used to implement stack guard pages for pKVM nVHE hypervisor
(in a subsequent patch in the series).

Credits to Quentin Perret <qperret@google.com> for the idea of moving
private VA allocation out of __pkvm_create_private_mapping()

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - PAGE_ALIGN the size in __pkvm_create_private_mapping(), per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update kernel-doc for pkvm_alloc_private_va_range() and add
    return description, per Stephen
  - Update pkvm_alloc_private_va_range() to return an int error code,
    per Stephen
  - Update __pkvm_create_private_mapping to return an in error code,
    per Quentin
  - Update callers of __pkvm_create_private_mapping() to handle new
    return value and params.

Changes in v5:
  - Align private allocations based on the order of their size, per Marc

Changes in v4:
  - Handle null ptr in pkvm_alloc_private_va_range() and replace
    IS_ERR_OR_NULL checks in callers with IS_ERR checks, per Fuad
  - Fix kernel-doc comments format, per Fuad
  - Format __pkvm_create_private_mapping() prototype args (< 80 col), per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark

Changes in v2:
  - Allow specifying an alignment for the private VA allocations, per Marc


 arch/arm64/kvm/hyp/include/nvhe/mm.h |  6 ++-
 arch/arm64/kvm/hyp/nvhe/hyp-main.c   | 18 ++++++-
 arch/arm64/kvm/hyp/nvhe/mm.c         | 78 ++++++++++++++++++----------
 3 files changed, 72 insertions(+), 30 deletions(-)

diff --git a/arch/arm64/kvm/hyp/include/nvhe/mm.h b/arch/arm64/kvm/hyp/include/nvhe/mm.h
index 2d08510c6cc1..42d8eb9bfe72 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mm.h
@@ -19,8 +19,10 @@ int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back);
 int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot);
 int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
 int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot);
-unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
-					    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_alloc_private_va_range(size_t size, unsigned long *haddr);
 
 static inline void hyp_vmemmap_range(phys_addr_t phys, unsigned long size,
 				     unsigned long *start, unsigned long *end)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 5e2197db0d32..3cea4b6ac23e 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -160,7 +160,23 @@ static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ct
 	DECLARE_REG(size_t, size, host_ctxt, 2);
 	DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3);
 
-	cpu_reg(host_ctxt, 1) = __pkvm_create_private_mapping(phys, size, prot);
+	/*
+	 * __pkvm_create_private_mapping() populates a pointer with the
+	 * hypervisor start address of the allocation.
+	 *
+	 * However, handle___pkvm_create_private_mapping() hypercall crosses the
+	 * EL1/EL2 boundary so the pointer would not be valid in this context.
+	 *
+	 * Instead pass the allocation address as the return value (or return
+	 * ERR_PTR() on failure).
+	 */
+	unsigned long haddr;
+	int err = __pkvm_create_private_mapping(phys, size, prot, &haddr);
+
+	if (err)
+		haddr = (unsigned long)ERR_PTR(err);
+
+	cpu_reg(host_ctxt, 1) = haddr;
 }
 
 static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c
index cdbe8e246418..96193cb31a39 100644
--- a/arch/arm64/kvm/hyp/nvhe/mm.c
+++ b/arch/arm64/kvm/hyp/nvhe/mm.c
@@ -37,36 +37,60 @@ static int __pkvm_create_mappings(unsigned long start, unsigned long size,
 	return err;
 }
 
-unsigned long __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
-					    enum kvm_pgtable_prot prot)
+/**
+ * pkvm_alloc_private_va_range - Allocates a private VA range.
+ * @size:	The size of the VA range to reserve.
+ * @haddr:	The hypervisor virtual start address of the allocation.
+ *
+ * The private virtual address (VA) range is allocated above __io_map_base
+ * and aligned based on the order of @size.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr)
 {
-	unsigned long addr;
-	int err;
+	unsigned long base, addr;
+	int ret = 0;
 
 	hyp_spin_lock(&pkvm_pgd_lock);
 
-	size = PAGE_ALIGN(size + offset_in_page(phys));
-	addr = __io_map_base;
-	__io_map_base += size;
+	/* Align the allocation based on the order of its size */
+	addr = ALIGN(__io_map_base, PAGE_SIZE << get_order(size));
 
-	/* Are we overflowing on the vmemmap ? */
-	if (__io_map_base > __hyp_vmemmap) {
-		__io_map_base -= size;
-		addr = (unsigned long)ERR_PTR(-ENOMEM);
-		goto out;
-	}
+	/* The allocated size is always a multiple of PAGE_SIZE */
+	base = addr + PAGE_ALIGN(size);
 
-	err = kvm_pgtable_hyp_map(&pkvm_pgtable, addr, size, phys, prot);
-	if (err) {
-		addr = (unsigned long)ERR_PTR(err);
-		goto out;
+	/* Are we overflowing on the vmemmap ? */
+	if (!addr || base > __hyp_vmemmap)
+		ret = -ENOMEM;
+	else {
+		__io_map_base = base;
+		*haddr = addr;
 	}
 
-	addr = addr + offset_in_page(phys);
-out:
 	hyp_spin_unlock(&pkvm_pgd_lock);
 
-	return addr;
+	return ret;
+}
+
+int __pkvm_create_private_mapping(phys_addr_t phys, size_t size,
+				  enum kvm_pgtable_prot prot,
+				  unsigned long *haddr)
+{
+	unsigned long addr;
+	int err;
+
+	size = PAGE_ALIGN(size + offset_in_page(phys));
+	err = pkvm_alloc_private_va_range(size, &addr);
+	if (err)
+		return err;
+
+	err = __pkvm_create_mappings(addr, size, phys, prot);
+	if (err)
+		return err;
+
+	*haddr = addr + offset_in_page(phys);
+	return err;
 }
 
 int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot)
@@ -146,7 +170,8 @@ int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot)
 int hyp_map_vectors(void)
 {
 	phys_addr_t phys;
-	void *bp_base;
+	unsigned long bp_base;
+	int ret;
 
 	if (!kvm_system_needs_idmapped_vectors()) {
 		__hyp_bp_vect_base = __bp_harden_hyp_vecs;
@@ -154,13 +179,12 @@ int hyp_map_vectors(void)
 	}
 
 	phys = __hyp_pa(__bp_harden_hyp_vecs);
-	bp_base = (void *)__pkvm_create_private_mapping(phys,
-							__BP_HARDEN_HYP_VECS_SZ,
-							PAGE_HYP_EXEC);
-	if (IS_ERR_OR_NULL(bp_base))
-		return PTR_ERR(bp_base);
+	ret = __pkvm_create_private_mapping(phys, __BP_HARDEN_HYP_VECS_SZ,
+					    PAGE_HYP_EXEC, &bp_base);
+	if (ret)
+		return ret;
 
-	__hyp_bp_vect_base = bp_base;
+	__hyp_bp_vect_base = (void *)bp_base;
 
 	return 0;
 }
-- 
2.36.0.rc0.470.gd361397f0d-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v8 3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack

[Kalesh Singh]

Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series).

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - Don't expose hyp_pgtable and kvm_hyp_pgd_mutex. Instead use
    __create_hyp_mappings() helper, per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update call to hyp_alloc_private_va_range() (return val and params)

Changes in v5:
  - Use a single allocation for stack and guard pages to ensure they
    are contiguous, per Marc

Changes in v4:
  - Replace IS_ERR_OR_NULL check with IS_ERR check now that
    hyp_alloc_private_va_range() returns an error for null
    pointer, per Fuad
  - Format comments to < 80 cols, per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark


 arch/arm64/include/asm/kvm_asm.h |  1 +
 arch/arm64/include/asm/kvm_mmu.h |  2 ++
 arch/arm64/kvm/arm.c             | 37 +++++++++++++++++++++++++++++---
 arch/arm64/kvm/mmu.c             |  4 ++--
 4 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index d5b0386ef765..2e277f2ed671 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -169,6 +169,7 @@ struct kvm_nvhe_init_params {
 	unsigned long tcr_el2;
 	unsigned long tpidr_el2;
 	unsigned long stack_hyp_va;
+	unsigned long stack_pa;
 	phys_addr_t pgd_pa;
 	unsigned long hcr_el2;
 	unsigned long vttbr;
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index a50cbb5ba402..b208da3bebec 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -154,6 +154,8 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v)
 int kvm_share_hyp(void *from, void *to);
 void kvm_unshare_hyp(void *from, void *to);
 int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
+int __create_hyp_mappings(unsigned long start, unsigned long size,
+			  unsigned long phys, enum kvm_pgtable_prot prot);
 int hyp_alloc_private_va_range(size_t size, unsigned long *haddr);
 int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 			   void __iomem **kaddr,
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 523bc934fe2f..dd257d9f21a2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1483,7 +1483,6 @@ static void cpu_prepare_hyp_mode(int cpu)
 	tcr |= (idmap_t0sz & GENMASK(TCR_TxSZ_WIDTH - 1, 0)) << TCR_T0SZ_OFFSET;
 	params->tcr_el2 = tcr;
 
-	params->stack_hyp_va = kern_hyp_va(per_cpu(kvm_arm_hyp_stack_page, cpu) + PAGE_SIZE);
 	params->pgd_pa = kvm_mmu_get_httbr();
 	if (is_protected_kvm_enabled())
 		params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS;
@@ -1933,14 +1932,46 @@ static int init_hyp_mode(void)
 	 * Map the Hyp stack pages
 	 */
 	for_each_possible_cpu(cpu) {
+		struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
 		char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu);
-		err = create_hyp_mappings(stack_page, stack_page + PAGE_SIZE,
-					  PAGE_HYP);
+		unsigned long hyp_addr;
 
+		/*
+		 * 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.
+		 */
+		err = hyp_alloc_private_va_range(PAGE_SIZE * 2, &hyp_addr);
+		if (err) {
+			kvm_err("Cannot allocate hyp stack guard page\n");
+			goto out_err;
+		}
+
+		/*
+		 * 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.
+		 */
+		err = __create_hyp_mappings(hyp_addr + PAGE_SIZE, PAGE_SIZE,
+					    __pa(stack_page), PAGE_HYP);
 		if (err) {
 			kvm_err("Cannot map hyp stack\n");
 			goto out_err;
 		}
+
+		/*
+		 * Save the stack PA in nvhe_init_params. This will be needed
+		 * to recreate the stack mapping in protected nVHE mode.
+		 * __hyp_pa() won't do the right thing there, since the stack
+		 * has been mapped in the flexible private VA space.
+		 */
+		params->stack_pa = __pa(stack_page);
+
+		params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE);
 	}
 
 	for_each_possible_cpu(cpu) {
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 7de1e02ebfd1..088e14eae4cf 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -258,8 +258,8 @@ static bool kvm_host_owns_hyp_mappings(void)
 	return true;
 }
 
-static int __create_hyp_mappings(unsigned long start, unsigned long size,
-				 unsigned long phys, enum kvm_pgtable_prot prot)
+int __create_hyp_mappings(unsigned long start, unsigned long size,
+			  unsigned long phys, enum kvm_pgtable_prot prot)
 {
 	int err;
 
-- 
2.36.0.rc0.470.gd361397f0d-goog

[PATCH v8 3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack

[Kalesh Singh]

Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series).

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - Don't expose hyp_pgtable and kvm_hyp_pgd_mutex. Instead use
    __create_hyp_mappings() helper, per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update call to hyp_alloc_private_va_range() (return val and params)

Changes in v5:
  - Use a single allocation for stack and guard pages to ensure they
    are contiguous, per Marc

Changes in v4:
  - Replace IS_ERR_OR_NULL check with IS_ERR check now that
    hyp_alloc_private_va_range() returns an error for null
    pointer, per Fuad
  - Format comments to < 80 cols, per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark


 arch/arm64/include/asm/kvm_asm.h |  1 +
 arch/arm64/include/asm/kvm_mmu.h |  2 ++
 arch/arm64/kvm/arm.c             | 37 +++++++++++++++++++++++++++++---
 arch/arm64/kvm/mmu.c             |  4 ++--
 4 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index d5b0386ef765..2e277f2ed671 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -169,6 +169,7 @@ struct kvm_nvhe_init_params {
 	unsigned long tcr_el2;
 	unsigned long tpidr_el2;
 	unsigned long stack_hyp_va;
+	unsigned long stack_pa;
 	phys_addr_t pgd_pa;
 	unsigned long hcr_el2;
 	unsigned long vttbr;
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index a50cbb5ba402..b208da3bebec 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -154,6 +154,8 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v)
 int kvm_share_hyp(void *from, void *to);
 void kvm_unshare_hyp(void *from, void *to);
 int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
+int __create_hyp_mappings(unsigned long start, unsigned long size,
+			  unsigned long phys, enum kvm_pgtable_prot prot);
 int hyp_alloc_private_va_range(size_t size, unsigned long *haddr);
 int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 			   void __iomem **kaddr,
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 523bc934fe2f..dd257d9f21a2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1483,7 +1483,6 @@ static void cpu_prepare_hyp_mode(int cpu)
 	tcr |= (idmap_t0sz & GENMASK(TCR_TxSZ_WIDTH - 1, 0)) << TCR_T0SZ_OFFSET;
 	params->tcr_el2 = tcr;
 
-	params->stack_hyp_va = kern_hyp_va(per_cpu(kvm_arm_hyp_stack_page, cpu) + PAGE_SIZE);
 	params->pgd_pa = kvm_mmu_get_httbr();
 	if (is_protected_kvm_enabled())
 		params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS;
@@ -1933,14 +1932,46 @@ static int init_hyp_mode(void)
 	 * Map the Hyp stack pages
 	 */
 	for_each_possible_cpu(cpu) {
+		struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
 		char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu);
-		err = create_hyp_mappings(stack_page, stack_page + PAGE_SIZE,
-					  PAGE_HYP);
+		unsigned long hyp_addr;
 
+		/*
+		 * 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.
+		 */
+		err = hyp_alloc_private_va_range(PAGE_SIZE * 2, &hyp_addr);
+		if (err) {
+			kvm_err("Cannot allocate hyp stack guard page\n");
+			goto out_err;
+		}
+
+		/*
+		 * 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.
+		 */
+		err = __create_hyp_mappings(hyp_addr + PAGE_SIZE, PAGE_SIZE,
+					    __pa(stack_page), PAGE_HYP);
 		if (err) {
 			kvm_err("Cannot map hyp stack\n");
 			goto out_err;
 		}
+
+		/*
+		 * Save the stack PA in nvhe_init_params. This will be needed
+		 * to recreate the stack mapping in protected nVHE mode.
+		 * __hyp_pa() won't do the right thing there, since the stack
+		 * has been mapped in the flexible private VA space.
+		 */
+		params->stack_pa = __pa(stack_page);
+
+		params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE);
 	}
 
 	for_each_possible_cpu(cpu) {
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 7de1e02ebfd1..088e14eae4cf 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -258,8 +258,8 @@ static bool kvm_host_owns_hyp_mappings(void)
 	return true;
 }
 
-static int __create_hyp_mappings(unsigned long start, unsigned long size,
-				 unsigned long phys, enum kvm_pgtable_prot prot)
+int __create_hyp_mappings(unsigned long start, unsigned long size,
+			  unsigned long phys, enum kvm_pgtable_prot prot)
 {
 	int err;
 
-- 
2.36.0.rc0.470.gd361397f0d-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v8 3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack

[Kalesh Singh]

Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series).

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - Don't expose hyp_pgtable and kvm_hyp_pgd_mutex. Instead use
    __create_hyp_mappings() helper, per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update call to hyp_alloc_private_va_range() (return val and params)

Changes in v5:
  - Use a single allocation for stack and guard pages to ensure they
    are contiguous, per Marc

Changes in v4:
  - Replace IS_ERR_OR_NULL check with IS_ERR check now that
    hyp_alloc_private_va_range() returns an error for null
    pointer, per Fuad
  - Format comments to < 80 cols, per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark


 arch/arm64/include/asm/kvm_asm.h |  1 +
 arch/arm64/include/asm/kvm_mmu.h |  2 ++
 arch/arm64/kvm/arm.c             | 37 +++++++++++++++++++++++++++++---
 arch/arm64/kvm/mmu.c             |  4 ++--
 4 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index d5b0386ef765..2e277f2ed671 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -169,6 +169,7 @@ struct kvm_nvhe_init_params {
 	unsigned long tcr_el2;
 	unsigned long tpidr_el2;
 	unsigned long stack_hyp_va;
+	unsigned long stack_pa;
 	phys_addr_t pgd_pa;
 	unsigned long hcr_el2;
 	unsigned long vttbr;
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index a50cbb5ba402..b208da3bebec 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -154,6 +154,8 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v)
 int kvm_share_hyp(void *from, void *to);
 void kvm_unshare_hyp(void *from, void *to);
 int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot);
+int __create_hyp_mappings(unsigned long start, unsigned long size,
+			  unsigned long phys, enum kvm_pgtable_prot prot);
 int hyp_alloc_private_va_range(size_t size, unsigned long *haddr);
 int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 			   void __iomem **kaddr,
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 523bc934fe2f..dd257d9f21a2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1483,7 +1483,6 @@ static void cpu_prepare_hyp_mode(int cpu)
 	tcr |= (idmap_t0sz & GENMASK(TCR_TxSZ_WIDTH - 1, 0)) << TCR_T0SZ_OFFSET;
 	params->tcr_el2 = tcr;
 
-	params->stack_hyp_va = kern_hyp_va(per_cpu(kvm_arm_hyp_stack_page, cpu) + PAGE_SIZE);
 	params->pgd_pa = kvm_mmu_get_httbr();
 	if (is_protected_kvm_enabled())
 		params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS;
@@ -1933,14 +1932,46 @@ static int init_hyp_mode(void)
 	 * Map the Hyp stack pages
 	 */
 	for_each_possible_cpu(cpu) {
+		struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
 		char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu);
-		err = create_hyp_mappings(stack_page, stack_page + PAGE_SIZE,
-					  PAGE_HYP);
+		unsigned long hyp_addr;
 
+		/*
+		 * 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.
+		 */
+		err = hyp_alloc_private_va_range(PAGE_SIZE * 2, &hyp_addr);
+		if (err) {
+			kvm_err("Cannot allocate hyp stack guard page\n");
+			goto out_err;
+		}
+
+		/*
+		 * 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.
+		 */
+		err = __create_hyp_mappings(hyp_addr + PAGE_SIZE, PAGE_SIZE,
+					    __pa(stack_page), PAGE_HYP);
 		if (err) {
 			kvm_err("Cannot map hyp stack\n");
 			goto out_err;
 		}
+
+		/*
+		 * Save the stack PA in nvhe_init_params. This will be needed
+		 * to recreate the stack mapping in protected nVHE mode.
+		 * __hyp_pa() won't do the right thing there, since the stack
+		 * has been mapped in the flexible private VA space.
+		 */
+		params->stack_pa = __pa(stack_page);
+
+		params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE);
 	}
 
 	for_each_possible_cpu(cpu) {
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 7de1e02ebfd1..088e14eae4cf 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -258,8 +258,8 @@ static bool kvm_host_owns_hyp_mappings(void)
 	return true;
 }
 
-static int __create_hyp_mappings(unsigned long start, unsigned long size,
-				 unsigned long phys, enum kvm_pgtable_prot prot)
+int __create_hyp_mappings(unsigned long start, unsigned long size,
+			  unsigned long phys, enum kvm_pgtable_prot prot)
 {
 	int err;
 
-- 
2.36.0.rc0.470.gd361397f0d-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v8 4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack

[Kalesh Singh]

Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series)

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update call to pkvm_alloc_private_va_range() (return val and params)

Changes in v5:
  - Use a single allocation for stack and guard pages to ensure they
    are contiguous, per Marc

Changes in v4:
  - Replace IS_ERR_OR_NULL check with IS_ERR check now that
    pkvm_alloc_private_va_range() returns an error for null
    pointer, per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark

 arch/arm64/kvm/hyp/nvhe/setup.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 27af337f9fea..e8d4ea2fcfa0 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -99,17 +99,42 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
 		return ret;
 
 	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);
 		ret = pkvm_create_mappings(start, end, PAGE_HYP);
 		if (ret)
 			return ret;
 
-		end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va;
-		start = end - PAGE_SIZE;
-		ret = pkvm_create_mappings(start, end, PAGE_HYP);
+		/*
+		 * 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);
+		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);
 	}
 
 	/*
-- 
2.36.0.rc0.470.gd361397f0d-goog

[PATCH v8 4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack

[Kalesh Singh]

Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series)

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update call to pkvm_alloc_private_va_range() (return val and params)

Changes in v5:
  - Use a single allocation for stack and guard pages to ensure they
    are contiguous, per Marc

Changes in v4:
  - Replace IS_ERR_OR_NULL check with IS_ERR check now that
    pkvm_alloc_private_va_range() returns an error for null
    pointer, per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark

 arch/arm64/kvm/hyp/nvhe/setup.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 27af337f9fea..e8d4ea2fcfa0 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -99,17 +99,42 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
 		return ret;
 
 	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);
 		ret = pkvm_create_mappings(start, end, PAGE_HYP);
 		if (ret)
 			return ret;
 
-		end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va;
-		start = end - PAGE_SIZE;
-		ret = pkvm_create_mappings(start, end, PAGE_HYP);
+		/*
+		 * 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);
+		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);
 	}
 
 	/*
-- 
2.36.0.rc0.470.gd361397f0d-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v8 4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack

[Kalesh Singh]

Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series)

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v6:
  - Update call to pkvm_alloc_private_va_range() (return val and params)

Changes in v5:
  - Use a single allocation for stack and guard pages to ensure they
    are contiguous, per Marc

Changes in v4:
  - Replace IS_ERR_OR_NULL check with IS_ERR check now that
    pkvm_alloc_private_va_range() returns an error for null
    pointer, per Fuad

Changes in v3:
  - Handle null ptr in IS_ERR_OR_NULL checks, per Mark

 arch/arm64/kvm/hyp/nvhe/setup.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 27af337f9fea..e8d4ea2fcfa0 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -99,17 +99,42 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
 		return ret;
 
 	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);
 		ret = pkvm_create_mappings(start, end, PAGE_HYP);
 		if (ret)
 			return ret;
 
-		end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va;
-		start = end - PAGE_SIZE;
-		ret = pkvm_create_mappings(start, end, PAGE_HYP);
+		/*
+		 * 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);
+		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);
 	}
 
 	/*
-- 
2.36.0.rc0.470.gd361397f0d-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

[PATCH v8 5/6] KVM: arm64: Detect and handle hypervisor stack overflows

[Kalesh Singh]

The hypervisor stacks (for both nVHE Hyp mode and nVHE protected mode)
are aligned such  that any valid stack address has PAGE_SHIFT bit as 1.
This allows us to conveniently check for overflow in the exception entry
without corrupting any GPRs. We won't recover from a stack overflow so
panic the hypervisor.

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - branch to hyp_panic_bad_stack(), instead of branch and link, per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v5:
  - Valid stack addresses now have PAGE_SHIFT bit as 1 instead of 0

Changes in v3:
  - Remove test_sp_overflow macro, per Mark
  - Add asmlinkage attribute for hyp_panic, hyp_panic_bad_stack, per Ard


 arch/arm64/kvm/hyp/nvhe/host.S   | 24 ++++++++++++++++++++++++
 arch/arm64/kvm/hyp/nvhe/switch.c |  7 ++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
index 3d613e721a75..09b5254fb497 100644
--- a/arch/arm64/kvm/hyp/nvhe/host.S
+++ b/arch/arm64/kvm/hyp/nvhe/host.S
@@ -153,6 +153,18 @@ SYM_FUNC_END(__host_hvc)
 
 .macro invalid_host_el2_vect
 	.align 7
+
+	/*
+	 * Test whether the SP has overflowed, without corrupting a GPR.
+	 * nVHE hypervisor stacks are aligned so that the PAGE_SHIFT bit
+	 * of SP should always be 1.
+	 */
+	add	sp, sp, x0			// sp' = sp + x0
+	sub	x0, sp, x0			// x0' = sp' - x0 = (sp + x0) - x0 = sp
+	tbz	x0, #PAGE_SHIFT, .L__hyp_sp_overflow\@
+	sub	x0, sp, x0			// x0'' = sp' - x0' = (sp + x0) - sp = x0
+	sub	sp, sp, x0			// sp'' = sp' - x0 = (sp + x0) - x0 = sp
+
 	/* If a guest is loaded, panic out of it. */
 	stp	x0, x1, [sp, #-16]!
 	get_loaded_vcpu x0, x1
@@ -165,6 +177,18 @@ SYM_FUNC_END(__host_hvc)
 	 * been partially clobbered by __host_enter.
 	 */
 	b	hyp_panic
+
+.L__hyp_sp_overflow\@:
+	/*
+	 * Reset SP to the top of the stack, to allow handling the hyp_panic.
+	 * This corrupts the stack but is ok, since we won't be attempting
+	 * any unwinding here.
+	 */
+	ldr_this_cpu	x0, kvm_init_params + NVHE_INIT_STACK_HYP_VA, x1
+	mov	sp, x0
+
+	b	hyp_panic_bad_stack
+	ASM_BUG()
 .endm
 
 .macro invalid_host_el1_vect
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 6410d21d8695..703a5d3f611b 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -347,7 +347,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 	return exit_code;
 }
 
-void __noreturn hyp_panic(void)
+asmlinkage void __noreturn hyp_panic(void)
 {
 	u64 spsr = read_sysreg_el2(SYS_SPSR);
 	u64 elr = read_sysreg_el2(SYS_ELR);
@@ -369,6 +369,11 @@ void __noreturn hyp_panic(void)
 	unreachable();
 }
 
+asmlinkage void __noreturn hyp_panic_bad_stack(void)
+{
+	hyp_panic();
+}
+
 asmlinkage void kvm_unexpected_el2_exception(void)
 {
 	return __kvm_unexpected_el2_exception();
-- 
2.36.0.rc0.470.gd361397f0d-goog

[PATCH v8 5/6] KVM: arm64: Detect and handle hypervisor stack overflows

[Kalesh Singh]

The hypervisor stacks (for both nVHE Hyp mode and nVHE protected mode)
are aligned such  that any valid stack address has PAGE_SHIFT bit as 1.
This allows us to conveniently check for overflow in the exception entry
without corrupting any GPRs. We won't recover from a stack overflow so
panic the hypervisor.

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - branch to hyp_panic_bad_stack(), instead of branch and link, per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v5:
  - Valid stack addresses now have PAGE_SHIFT bit as 1 instead of 0

Changes in v3:
  - Remove test_sp_overflow macro, per Mark
  - Add asmlinkage attribute for hyp_panic, hyp_panic_bad_stack, per Ard


 arch/arm64/kvm/hyp/nvhe/host.S   | 24 ++++++++++++++++++++++++
 arch/arm64/kvm/hyp/nvhe/switch.c |  7 ++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
index 3d613e721a75..09b5254fb497 100644
--- a/arch/arm64/kvm/hyp/nvhe/host.S
+++ b/arch/arm64/kvm/hyp/nvhe/host.S
@@ -153,6 +153,18 @@ SYM_FUNC_END(__host_hvc)
 
 .macro invalid_host_el2_vect
 	.align 7
+
+	/*
+	 * Test whether the SP has overflowed, without corrupting a GPR.
+	 * nVHE hypervisor stacks are aligned so that the PAGE_SHIFT bit
+	 * of SP should always be 1.
+	 */
+	add	sp, sp, x0			// sp' = sp + x0
+	sub	x0, sp, x0			// x0' = sp' - x0 = (sp + x0) - x0 = sp
+	tbz	x0, #PAGE_SHIFT, .L__hyp_sp_overflow\@
+	sub	x0, sp, x0			// x0'' = sp' - x0' = (sp + x0) - sp = x0
+	sub	sp, sp, x0			// sp'' = sp' - x0 = (sp + x0) - x0 = sp
+
 	/* If a guest is loaded, panic out of it. */
 	stp	x0, x1, [sp, #-16]!
 	get_loaded_vcpu x0, x1
@@ -165,6 +177,18 @@ SYM_FUNC_END(__host_hvc)
 	 * been partially clobbered by __host_enter.
 	 */
 	b	hyp_panic
+
+.L__hyp_sp_overflow\@:
+	/*
+	 * Reset SP to the top of the stack, to allow handling the hyp_panic.
+	 * This corrupts the stack but is ok, since we won't be attempting
+	 * any unwinding here.
+	 */
+	ldr_this_cpu	x0, kvm_init_params + NVHE_INIT_STACK_HYP_VA, x1
+	mov	sp, x0
+
+	b	hyp_panic_bad_stack
+	ASM_BUG()
 .endm
 
 .macro invalid_host_el1_vect
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 6410d21d8695..703a5d3f611b 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -347,7 +347,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 	return exit_code;
 }
 
-void __noreturn hyp_panic(void)
+asmlinkage void __noreturn hyp_panic(void)
 {
 	u64 spsr = read_sysreg_el2(SYS_SPSR);
 	u64 elr = read_sysreg_el2(SYS_ELR);
@@ -369,6 +369,11 @@ void __noreturn hyp_panic(void)
 	unreachable();
 }
 
+asmlinkage void __noreturn hyp_panic_bad_stack(void)
+{
+	hyp_panic();
+}
+
 asmlinkage void kvm_unexpected_el2_exception(void)
 {
 	return __kvm_unexpected_el2_exception();
-- 
2.36.0.rc0.470.gd361397f0d-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v8 5/6] KVM: arm64: Detect and handle hypervisor stack overflows

[Kalesh Singh]

The hypervisor stacks (for both nVHE Hyp mode and nVHE protected mode)
are aligned such  that any valid stack address has PAGE_SHIFT bit as 1.
This allows us to conveniently check for overflow in the exception entry
without corrupting any GPRs. We won't recover from a stack overflow so
panic the hypervisor.

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - branch to hyp_panic_bad_stack(), instead of branch and link, per Marc

Changes in v7:
  - Add Fuad's Reviewed-by and Tested-by tags.

Changes in v5:
  - Valid stack addresses now have PAGE_SHIFT bit as 1 instead of 0

Changes in v3:
  - Remove test_sp_overflow macro, per Mark
  - Add asmlinkage attribute for hyp_panic, hyp_panic_bad_stack, per Ard


 arch/arm64/kvm/hyp/nvhe/host.S   | 24 ++++++++++++++++++++++++
 arch/arm64/kvm/hyp/nvhe/switch.c |  7 ++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
index 3d613e721a75..09b5254fb497 100644
--- a/arch/arm64/kvm/hyp/nvhe/host.S
+++ b/arch/arm64/kvm/hyp/nvhe/host.S
@@ -153,6 +153,18 @@ SYM_FUNC_END(__host_hvc)
 
 .macro invalid_host_el2_vect
 	.align 7
+
+	/*
+	 * Test whether the SP has overflowed, without corrupting a GPR.
+	 * nVHE hypervisor stacks are aligned so that the PAGE_SHIFT bit
+	 * of SP should always be 1.
+	 */
+	add	sp, sp, x0			// sp' = sp + x0
+	sub	x0, sp, x0			// x0' = sp' - x0 = (sp + x0) - x0 = sp
+	tbz	x0, #PAGE_SHIFT, .L__hyp_sp_overflow\@
+	sub	x0, sp, x0			// x0'' = sp' - x0' = (sp + x0) - sp = x0
+	sub	sp, sp, x0			// sp'' = sp' - x0 = (sp + x0) - x0 = sp
+
 	/* If a guest is loaded, panic out of it. */
 	stp	x0, x1, [sp, #-16]!
 	get_loaded_vcpu x0, x1
@@ -165,6 +177,18 @@ SYM_FUNC_END(__host_hvc)
 	 * been partially clobbered by __host_enter.
 	 */
 	b	hyp_panic
+
+.L__hyp_sp_overflow\@:
+	/*
+	 * Reset SP to the top of the stack, to allow handling the hyp_panic.
+	 * This corrupts the stack but is ok, since we won't be attempting
+	 * any unwinding here.
+	 */
+	ldr_this_cpu	x0, kvm_init_params + NVHE_INIT_STACK_HYP_VA, x1
+	mov	sp, x0
+
+	b	hyp_panic_bad_stack
+	ASM_BUG()
 .endm
 
 .macro invalid_host_el1_vect
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 6410d21d8695..703a5d3f611b 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -347,7 +347,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 	return exit_code;
 }
 
-void __noreturn hyp_panic(void)
+asmlinkage void __noreturn hyp_panic(void)
 {
 	u64 spsr = read_sysreg_el2(SYS_SPSR);
 	u64 elr = read_sysreg_el2(SYS_ELR);
@@ -369,6 +369,11 @@ void __noreturn hyp_panic(void)
 	unreachable();
 }
 
+asmlinkage void __noreturn hyp_panic_bad_stack(void)
+{
+	hyp_panic();
+}
+
 asmlinkage void kvm_unexpected_el2_exception(void)
 {
 	return __kvm_unexpected_el2_exception();
-- 
2.36.0.rc0.470.gd361397f0d-goog

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[PATCH v8 6/6] KVM: arm64: Symbolize the nVHE HYP addresses

[Kalesh Singh]

Reintroduce the __kvm_nvhe_ symbols in kallsyms, ignoring the local
symbols in this namespace. The local symbols are not informative and
can cause aliasing issues when symbolizing the addresses.

With the necessary symbols now in kallsyms we can symbolize nVHE
addresses using the %p print format specifier:

[   98.916444][  T426] kvm [426]: nVHE hyp panic at: [<ffffffc0096156fc>] __kvm_nvhe_overflow_stack+0x8/0x34!

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - Also ignore local symbols prefixed by '.L' in KVM nvhe namespace,
    per Marc

Changes in v6:
  - Add Fuad's Reviewed-by and Tested-by tags.
  
Changes in v2:
  - Fix printk warnings - %p expects (void *)


 arch/arm64/kvm/handle_exit.c | 13 +++++--------
 scripts/kallsyms.c           |  3 ++-
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 97fe14aab1a3..a377b871bf58 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -295,13 +295,8 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr,
 	u64 elr_in_kimg = __phys_to_kimg(elr_phys);
 	u64 hyp_offset = elr_in_kimg - kaslr_offset() - elr_virt;
 	u64 mode = spsr & PSR_MODE_MASK;
+	u64 panic_addr = elr_virt + hyp_offset;
 
-	/*
-	 * The nVHE hyp symbols are not included by kallsyms to avoid issues
-	 * with aliasing. That means that the symbols cannot be printed with the
-	 * "%pS" format specifier, so fall back to the vmlinux address if
-	 * there's no better option.
-	 */
 	if (mode != PSR_MODE_EL2t && mode != PSR_MODE_EL2h) {
 		kvm_err("Invalid host exception to nVHE hyp!\n");
 	} else if (ESR_ELx_EC(esr) == ESR_ELx_EC_BRK64 &&
@@ -321,9 +316,11 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr,
 		if (file)
 			kvm_err("nVHE hyp BUG at: %s:%u!\n", file, line);
 		else
-			kvm_err("nVHE hyp BUG at: %016llx!\n", elr_virt + hyp_offset);
+			kvm_err("nVHE hyp BUG at: [<%016llx>] %pB!\n", panic_addr,
+					(void *)panic_addr);
 	} else {
-		kvm_err("nVHE hyp panic at: %016llx!\n", elr_virt + hyp_offset);
+		kvm_err("nVHE hyp panic at: [<%016llx>] %pB!\n", panic_addr,
+				(void *)panic_addr);
 	}
 
 	/*
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 8caabddf817c..e6906f79833d 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -111,7 +111,8 @@ static bool is_ignored_symbol(const char *name, char type)
 		".L",			/* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */
 		"__crc_",		/* modversions */
 		"__efistub_",		/* arm64 EFI stub namespace */
-		"__kvm_nvhe_",		/* arm64 non-VHE KVM namespace */
+		"__kvm_nvhe_$",		/* arm64 local symbols in non-VHE KVM namespace */
+		"__kvm_nvhe_.L",	/* arm64 local symbols in non-VHE KVM namespace */
 		"__AArch64ADRPThunk_",	/* arm64 lld */
 		"__ARMV5PILongThunk_",	/* arm lld */
 		"__ARMV7PILongThunk_",
-- 
2.36.0.rc0.470.gd361397f0d-goog

[PATCH v8 6/6] KVM: arm64: Symbolize the nVHE HYP addresses

[Kalesh Singh]

Reintroduce the __kvm_nvhe_ symbols in kallsyms, ignoring the local
symbols in this namespace. The local symbols are not informative and
can cause aliasing issues when symbolizing the addresses.

With the necessary symbols now in kallsyms we can symbolize nVHE
addresses using the %p print format specifier:

[   98.916444][  T426] kvm [426]: nVHE hyp panic at: [<ffffffc0096156fc>] __kvm_nvhe_overflow_stack+0x8/0x34!

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - Also ignore local symbols prefixed by '.L' in KVM nvhe namespace,
    per Marc

Changes in v6:
  - Add Fuad's Reviewed-by and Tested-by tags.
  
Changes in v2:
  - Fix printk warnings - %p expects (void *)


 arch/arm64/kvm/handle_exit.c | 13 +++++--------
 scripts/kallsyms.c           |  3 ++-
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 97fe14aab1a3..a377b871bf58 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -295,13 +295,8 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr,
 	u64 elr_in_kimg = __phys_to_kimg(elr_phys);
 	u64 hyp_offset = elr_in_kimg - kaslr_offset() - elr_virt;
 	u64 mode = spsr & PSR_MODE_MASK;
+	u64 panic_addr = elr_virt + hyp_offset;
 
-	/*
-	 * The nVHE hyp symbols are not included by kallsyms to avoid issues
-	 * with aliasing. That means that the symbols cannot be printed with the
-	 * "%pS" format specifier, so fall back to the vmlinux address if
-	 * there's no better option.
-	 */
 	if (mode != PSR_MODE_EL2t && mode != PSR_MODE_EL2h) {
 		kvm_err("Invalid host exception to nVHE hyp!\n");
 	} else if (ESR_ELx_EC(esr) == ESR_ELx_EC_BRK64 &&
@@ -321,9 +316,11 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr,
 		if (file)
 			kvm_err("nVHE hyp BUG at: %s:%u!\n", file, line);
 		else
-			kvm_err("nVHE hyp BUG at: %016llx!\n", elr_virt + hyp_offset);
+			kvm_err("nVHE hyp BUG at: [<%016llx>] %pB!\n", panic_addr,
+					(void *)panic_addr);
 	} else {
-		kvm_err("nVHE hyp panic at: %016llx!\n", elr_virt + hyp_offset);
+		kvm_err("nVHE hyp panic at: [<%016llx>] %pB!\n", panic_addr,
+				(void *)panic_addr);
 	}
 
 	/*
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 8caabddf817c..e6906f79833d 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -111,7 +111,8 @@ static bool is_ignored_symbol(const char *name, char type)
 		".L",			/* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */
 		"__crc_",		/* modversions */
 		"__efistub_",		/* arm64 EFI stub namespace */
-		"__kvm_nvhe_",		/* arm64 non-VHE KVM namespace */
+		"__kvm_nvhe_$",		/* arm64 local symbols in non-VHE KVM namespace */
+		"__kvm_nvhe_.L",	/* arm64 local symbols in non-VHE KVM namespace */
 		"__AArch64ADRPThunk_",	/* arm64 lld */
 		"__ARMV5PILongThunk_",	/* arm lld */
 		"__ARMV7PILongThunk_",
-- 
2.36.0.rc0.470.gd361397f0d-goog


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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v8 6/6] KVM: arm64: Symbolize the nVHE HYP addresses

[Kalesh Singh]

Reintroduce the __kvm_nvhe_ symbols in kallsyms, ignoring the local
symbols in this namespace. The local symbols are not informative and
can cause aliasing issues when symbolizing the addresses.

With the necessary symbols now in kallsyms we can symbolize nVHE
addresses using the %p print format specifier:

[   98.916444][  T426] kvm [426]: nVHE hyp panic at: [<ffffffc0096156fc>] __kvm_nvhe_overflow_stack+0x8/0x34!

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
---

Changes in v8:
  - Also ignore local symbols prefixed by '.L' in KVM nvhe namespace,
    per Marc

Changes in v6:
  - Add Fuad's Reviewed-by and Tested-by tags.
  
Changes in v2:
  - Fix printk warnings - %p expects (void *)


 arch/arm64/kvm/handle_exit.c | 13 +++++--------
 scripts/kallsyms.c           |  3 ++-
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 97fe14aab1a3..a377b871bf58 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -295,13 +295,8 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr,
 	u64 elr_in_kimg = __phys_to_kimg(elr_phys);
 	u64 hyp_offset = elr_in_kimg - kaslr_offset() - elr_virt;
 	u64 mode = spsr & PSR_MODE_MASK;
+	u64 panic_addr = elr_virt + hyp_offset;
 
-	/*
-	 * The nVHE hyp symbols are not included by kallsyms to avoid issues
-	 * with aliasing. That means that the symbols cannot be printed with the
-	 * "%pS" format specifier, so fall back to the vmlinux address if
-	 * there's no better option.
-	 */
 	if (mode != PSR_MODE_EL2t && mode != PSR_MODE_EL2h) {
 		kvm_err("Invalid host exception to nVHE hyp!\n");
 	} else if (ESR_ELx_EC(esr) == ESR_ELx_EC_BRK64 &&
@@ -321,9 +316,11 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr,
 		if (file)
 			kvm_err("nVHE hyp BUG at: %s:%u!\n", file, line);
 		else
-			kvm_err("nVHE hyp BUG at: %016llx!\n", elr_virt + hyp_offset);
+			kvm_err("nVHE hyp BUG at: [<%016llx>] %pB!\n", panic_addr,
+					(void *)panic_addr);
 	} else {
-		kvm_err("nVHE hyp panic at: %016llx!\n", elr_virt + hyp_offset);
+		kvm_err("nVHE hyp panic at: [<%016llx>] %pB!\n", panic_addr,
+				(void *)panic_addr);
 	}
 
 	/*
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 8caabddf817c..e6906f79833d 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -111,7 +111,8 @@ static bool is_ignored_symbol(const char *name, char type)
 		".L",			/* local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */
 		"__crc_",		/* modversions */
 		"__efistub_",		/* arm64 EFI stub namespace */
-		"__kvm_nvhe_",		/* arm64 non-VHE KVM namespace */
+		"__kvm_nvhe_$",		/* arm64 local symbols in non-VHE KVM namespace */
+		"__kvm_nvhe_.L",	/* arm64 local symbols in non-VHE KVM namespace */
 		"__AArch64ADRPThunk_",	/* arm64 lld */
 		"__ARMV5PILongThunk_",	/* arm lld */
 		"__ARMV7PILongThunk_",
-- 
2.36.0.rc0.470.gd361397f0d-goog

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https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Re: [PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Marc Zyngier]

On Wed, 20 Apr 2022 14:42:51 -0700, Kalesh Singh wrote:
> This is v8 of the nVHE hypervisor stack enhancements. This version is based
> on 5.18-rc3.
> 
> Previous versions can be found at:
> v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
> v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
> v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
> v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
> v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
> v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
> v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/
> 
> [...]

Applied to next, thanks!

[1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()
      commit: 92abe0f81e1385afd8f1dc66206b5be9a514899b
[2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()
      commit: f922c13e778d6d5343d4576be785a8204c595113
[3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
      commit: ce3354318a57875dc59f4bb841662e95bfba03db
[4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
      commit: 1a919b17ef012ca0572bae759c27e5ea02bfb47f
[5/6] KVM: arm64: Detect and handle hypervisor stack overflows
      commit: 66de19fad9ef47c5376a99bb2b00661f1c788a94
[6/6] KVM: arm64: Symbolize the nVHE HYP addresses
      commit: 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Marc Zyngier]

On Wed, 20 Apr 2022 14:42:51 -0700, Kalesh Singh wrote:
> This is v8 of the nVHE hypervisor stack enhancements. This version is based
> on 5.18-rc3.
> 
> Previous versions can be found at:
> v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
> v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
> v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
> v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
> v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
> v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
> v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/
> 
> [...]

Applied to next, thanks!

[1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()
      commit: 92abe0f81e1385afd8f1dc66206b5be9a514899b
[2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()
      commit: f922c13e778d6d5343d4576be785a8204c595113
[3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
      commit: ce3354318a57875dc59f4bb841662e95bfba03db
[4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
      commit: 1a919b17ef012ca0572bae759c27e5ea02bfb47f
[5/6] KVM: arm64: Detect and handle hypervisor stack overflows
      commit: 66de19fad9ef47c5376a99bb2b00661f1c788a94
[6/6] KVM: arm64: Symbolize the nVHE HYP addresses
      commit: 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.



_______________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Marc Zyngier]

On Wed, 20 Apr 2022 14:42:51 -0700, Kalesh Singh wrote:
> This is v8 of the nVHE hypervisor stack enhancements. This version is based
> on 5.18-rc3.
> 
> Previous versions can be found at:
> v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
> v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
> v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
> v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
> v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
> v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
> v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/
> 
> [...]

Applied to next, thanks!

[1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()
      commit: 92abe0f81e1385afd8f1dc66206b5be9a514899b
[2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()
      commit: f922c13e778d6d5343d4576be785a8204c595113
[3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
      commit: ce3354318a57875dc59f4bb841662e95bfba03db
[4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
      commit: 1a919b17ef012ca0572bae759c27e5ea02bfb47f
[5/6] KVM: arm64: Detect and handle hypervisor stack overflows
      commit: 66de19fad9ef47c5376a99bb2b00661f1c788a94
[6/6] KVM: arm64: Symbolize the nVHE HYP addresses
      commit: 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.


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Re: [PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Kalesh Singh]

On Thu, Apr 28, 2022 at 12:55 PM Marc Zyngier <maz@kernel.org> wrote:
>
> On Wed, 20 Apr 2022 14:42:51 -0700, Kalesh Singh wrote:
> > This is v8 of the nVHE hypervisor stack enhancements. This version is based
> > on 5.18-rc3.
> >
> > Previous versions can be found at:
> > v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
> > v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
> > v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
> > v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
> > v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
> > v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
> > v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/
> >
> > [...]
>
> Applied to next, thanks!
>
> [1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()
>       commit: 92abe0f81e1385afd8f1dc66206b5be9a514899b
> [2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()
>       commit: f922c13e778d6d5343d4576be785a8204c595113
> [3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
>       commit: ce3354318a57875dc59f4bb841662e95bfba03db
> [4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
>       commit: 1a919b17ef012ca0572bae759c27e5ea02bfb47f
> [5/6] KVM: arm64: Detect and handle hypervisor stack overflows
>       commit: 66de19fad9ef47c5376a99bb2b00661f1c788a94
> [6/6] KVM: arm64: Symbolize the nVHE HYP addresses
>       commit: 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d

Thanks for applying these Marc.

I was wondering if instead of taking these through kvm-arm64/next,
could Catalin consolidated these in arm64 for-next/core with Mark
Ruthland's and Madhavan's stacktrace patches[1]? This avoids conflict
and would allow for the hypervisor unwinding changes[2] to apply
cleanly.

[1] https://lore.kernel.org/r/20220413145910.3060139-1-mark.rutland@arm.com/
[2]  https://lore.kernel.org/r/20220427184716.1949239-1-kaleshsingh@google.com/

Thanks,
Kalesh
>
> Cheers,
>
>         M.
> --
> Without deviation from the norm, progress is not possible.
>
>

Re: [PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Kalesh Singh]

On Thu, Apr 28, 2022 at 12:55 PM Marc Zyngier <maz@kernel.org> wrote:
>
> On Wed, 20 Apr 2022 14:42:51 -0700, Kalesh Singh wrote:
> > This is v8 of the nVHE hypervisor stack enhancements. This version is based
> > on 5.18-rc3.
> >
> > Previous versions can be found at:
> > v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
> > v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
> > v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
> > v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
> > v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
> > v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
> > v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/
> >
> > [...]
>
> Applied to next, thanks!
>
> [1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()
>       commit: 92abe0f81e1385afd8f1dc66206b5be9a514899b
> [2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()
>       commit: f922c13e778d6d5343d4576be785a8204c595113
> [3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
>       commit: ce3354318a57875dc59f4bb841662e95bfba03db
> [4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
>       commit: 1a919b17ef012ca0572bae759c27e5ea02bfb47f
> [5/6] KVM: arm64: Detect and handle hypervisor stack overflows
>       commit: 66de19fad9ef47c5376a99bb2b00661f1c788a94
> [6/6] KVM: arm64: Symbolize the nVHE HYP addresses
>       commit: 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d

Thanks for applying these Marc.

I was wondering if instead of taking these through kvm-arm64/next,
could Catalin consolidated these in arm64 for-next/core with Mark
Ruthland's and Madhavan's stacktrace patches[1]? This avoids conflict
and would allow for the hypervisor unwinding changes[2] to apply
cleanly.

[1] https://lore.kernel.org/r/20220413145910.3060139-1-mark.rutland@arm.com/
[2]  https://lore.kernel.org/r/20220427184716.1949239-1-kaleshsingh@google.com/

Thanks,
Kalesh
>
> Cheers,
>
>         M.
> --
> Without deviation from the norm, progress is not possible.
>
>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Kalesh Singh]

On Thu, Apr 28, 2022 at 12:55 PM Marc Zyngier <maz@kernel.org> wrote:
>
> On Wed, 20 Apr 2022 14:42:51 -0700, Kalesh Singh wrote:
> > This is v8 of the nVHE hypervisor stack enhancements. This version is based
> > on 5.18-rc3.
> >
> > Previous versions can be found at:
> > v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
> > v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
> > v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
> > v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
> > v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
> > v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
> > v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/
> >
> > [...]
>
> Applied to next, thanks!
>
> [1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()
>       commit: 92abe0f81e1385afd8f1dc66206b5be9a514899b
> [2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()
>       commit: f922c13e778d6d5343d4576be785a8204c595113
> [3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
>       commit: ce3354318a57875dc59f4bb841662e95bfba03db
> [4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
>       commit: 1a919b17ef012ca0572bae759c27e5ea02bfb47f
> [5/6] KVM: arm64: Detect and handle hypervisor stack overflows
>       commit: 66de19fad9ef47c5376a99bb2b00661f1c788a94
> [6/6] KVM: arm64: Symbolize the nVHE HYP addresses
>       commit: 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d

Thanks for applying these Marc.

I was wondering if instead of taking these through kvm-arm64/next,
could Catalin consolidated these in arm64 for-next/core with Mark
Ruthland's and Madhavan's stacktrace patches[1]? This avoids conflict
and would allow for the hypervisor unwinding changes[2] to apply
cleanly.

[1] https://lore.kernel.org/r/20220413145910.3060139-1-mark.rutland@arm.com/
[2]  https://lore.kernel.org/r/20220427184716.1949239-1-kaleshsingh@google.com/

Thanks,
Kalesh
>
> Cheers,
>
>         M.
> --
> Without deviation from the norm, progress is not possible.
>
>
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Re: [PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Marc Zyngier]

On Mon, 02 May 2022 17:54:45 +0100,
Kalesh Singh <kaleshsingh@google.com> wrote:
> 
> On Thu, Apr 28, 2022 at 12:55 PM Marc Zyngier <maz@kernel.org> wrote:
> >
> > On Wed, 20 Apr 2022 14:42:51 -0700, Kalesh Singh wrote:
> > > This is v8 of the nVHE hypervisor stack enhancements. This version is based
> > > on 5.18-rc3.
> > >
> > > Previous versions can be found at:
> > > v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
> > > v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
> > > v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
> > > v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
> > > v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
> > > v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
> > > v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/
> > >
> > > [...]
> >
> > Applied to next, thanks!
> >
> > [1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()
> >       commit: 92abe0f81e1385afd8f1dc66206b5be9a514899b
> > [2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()
> >       commit: f922c13e778d6d5343d4576be785a8204c595113
> > [3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
> >       commit: ce3354318a57875dc59f4bb841662e95bfba03db
> > [4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
> >       commit: 1a919b17ef012ca0572bae759c27e5ea02bfb47f
> > [5/6] KVM: arm64: Detect and handle hypervisor stack overflows
> >       commit: 66de19fad9ef47c5376a99bb2b00661f1c788a94
> > [6/6] KVM: arm64: Symbolize the nVHE HYP addresses
> >       commit: 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d
> 
> Thanks for applying these Marc.
> 
> I was wondering if instead of taking these through kvm-arm64/next,
> could Catalin consolidated these in arm64 for-next/core with Mark
> Ruthland's and Madhavan's stacktrace patches[1]? This avoids conflict
> and would allow for the hypervisor unwinding changes[2] to apply
> cleanly.

So far, there hasn't been any reported conflict. If Catalin needs to
merge the branch or part of it, it is stable anyway and can be pulled
from anywhere.

As for the rest of the stacktrace stuff, I haven't had a look yet.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Marc Zyngier]

On Mon, 02 May 2022 17:54:45 +0100,
Kalesh Singh <kaleshsingh@google.com> wrote:
> 
> On Thu, Apr 28, 2022 at 12:55 PM Marc Zyngier <maz@kernel.org> wrote:
> >
> > On Wed, 20 Apr 2022 14:42:51 -0700, Kalesh Singh wrote:
> > > This is v8 of the nVHE hypervisor stack enhancements. This version is based
> > > on 5.18-rc3.
> > >
> > > Previous versions can be found at:
> > > v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
> > > v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
> > > v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
> > > v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
> > > v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
> > > v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
> > > v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/
> > >
> > > [...]
> >
> > Applied to next, thanks!
> >
> > [1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()
> >       commit: 92abe0f81e1385afd8f1dc66206b5be9a514899b
> > [2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()
> >       commit: f922c13e778d6d5343d4576be785a8204c595113
> > [3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
> >       commit: ce3354318a57875dc59f4bb841662e95bfba03db
> > [4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
> >       commit: 1a919b17ef012ca0572bae759c27e5ea02bfb47f
> > [5/6] KVM: arm64: Detect and handle hypervisor stack overflows
> >       commit: 66de19fad9ef47c5376a99bb2b00661f1c788a94
> > [6/6] KVM: arm64: Symbolize the nVHE HYP addresses
> >       commit: 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d
> 
> Thanks for applying these Marc.
> 
> I was wondering if instead of taking these through kvm-arm64/next,
> could Catalin consolidated these in arm64 for-next/core with Mark
> Ruthland's and Madhavan's stacktrace patches[1]? This avoids conflict
> and would allow for the hypervisor unwinding changes[2] to apply
> cleanly.

So far, there hasn't been any reported conflict. If Catalin needs to
merge the branch or part of it, it is stable anyway and can be pulled
from anywhere.

As for the rest of the stacktrace stuff, I haven't had a look yet.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v8 0/6] KVM: arm64: Hypervisor stack enhancements

[Marc Zyngier]

On Mon, 02 May 2022 17:54:45 +0100,
Kalesh Singh <kaleshsingh@google.com> wrote:
> 
> On Thu, Apr 28, 2022 at 12:55 PM Marc Zyngier <maz@kernel.org> wrote:
> >
> > On Wed, 20 Apr 2022 14:42:51 -0700, Kalesh Singh wrote:
> > > This is v8 of the nVHE hypervisor stack enhancements. This version is based
> > > on 5.18-rc3.
> > >
> > > Previous versions can be found at:
> > > v7: https://lore.kernel.org/r/20220408200349.1529080-1-kaleshsingh@google.com/
> > > v6: https://lore.kernel.org/r/20220314200148.2695206-1-kaleshsingh@google.com/
> > > v5: https://lore.kernel.org/r/20220307184935.1704614-1-kaleshsingh@google.com/
> > > v4: https://lore.kernel.org/r/20220225033548.1912117-1-kaleshsingh@google.com/
> > > v3: https://lore.kernel.org/r/20220224051439.640768-1-kaleshsingh@google.com/
> > > v2: https://lore.kernel.org/r/20220222165212.2005066-1-kaleshsingh@google.com/
> > > v1: https://lore.kernel.org/r/20220210224220.4076151-1-kaleshsingh@google.com/
> > >
> > > [...]
> >
> > Applied to next, thanks!
> >
> > [1/6] KVM: arm64: Introduce hyp_alloc_private_va_range()
> >       commit: 92abe0f81e1385afd8f1dc66206b5be9a514899b
> > [2/6] KVM: arm64: Introduce pkvm_alloc_private_va_range()
> >       commit: f922c13e778d6d5343d4576be785a8204c595113
> > [3/6] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack
> >       commit: ce3354318a57875dc59f4bb841662e95bfba03db
> > [4/6] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
> >       commit: 1a919b17ef012ca0572bae759c27e5ea02bfb47f
> > [5/6] KVM: arm64: Detect and handle hypervisor stack overflows
> >       commit: 66de19fad9ef47c5376a99bb2b00661f1c788a94
> > [6/6] KVM: arm64: Symbolize the nVHE HYP addresses
> >       commit: 6ccf9cb557bd32073b0d68baed97f1bd8a40ff1d
> 
> Thanks for applying these Marc.
> 
> I was wondering if instead of taking these through kvm-arm64/next,
> could Catalin consolidated these in arm64 for-next/core with Mark
> Ruthland's and Madhavan's stacktrace patches[1]? This avoids conflict
> and would allow for the hypervisor unwinding changes[2] to apply
> cleanly.

So far, there hasn't been any reported conflict. If Catalin needs to
merge the branch or part of it, it is stable anyway and can be pulled
from anywhere.

As for the rest of the stacktrace stuff, I haven't had a look yet.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm