[GIT PULL 00/13] KVM: s390: Changes for 5.18 part1

[GIT PULL 00/13] KVM: s390: Changes for 5.18 part1

[Christian Borntraeger]

Paolo,

first part of the s390 parts of KVM for 5.18. This is on top of the fix
that went into Linus tree, so it will move kvm/next to something between
rc3 and rc4.

I added 2 later fixups for the storage key patches on top. Let me know if
you prefer them folded in.

We might do a 2nd pull request later on depending on timing, review and
other constraints
with
- rewritten selftest for memop
- ultravisor device (could also go via s390 tree)
- parts/all of Claudios lazy destroy
- parts/all of PCI passthru (could be later and might go via s390 tree as
  well via a topic branch)
- followup to guest entry/exit work if we find a small solution
- adapter interruption virtualization facility for secure guests

The following changes since commit 09a93c1df3eafa43bcdfd7bf837c574911f12f55:

  Merge tag 'kvm-s390-kernel-access' from emailed bundle (2022-02-09 09:14:22 -0800)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git  tags/kvm-s390-next-5.18-1

for you to fetch changes up to 3d9042f8b923810c169ece02d91c70ec498eff0b:

  KVM: s390: Add missing vm MEM_OP size check (2022-02-22 09:16:18 +0100)

----------------------------------------------------------------
KVM: s390: Changes for 5.18 part1

- add Claudio as Maintainer
- first step to do proper storage key checking
- testcase for missing memop check

----------------------------------------------------------------
Christian Borntraeger (1):
      KVM: s390: MAINTAINERS: promote Claudio Imbrenda

Janis Schoetterl-Glausch (11):
      s390/uaccess: Add copy_from/to_user_key functions
      KVM: s390: Honor storage keys when accessing guest memory
      KVM: s390: handle_tprot: Honor storage keys
      KVM: s390: selftests: Test TEST PROTECTION emulation
      KVM: s390: Add optional storage key checking to MEMOP IOCTL
      KVM: s390: Add vm IOCTL for key checked guest absolute memory access
      KVM: s390: Rename existing vcpu memop functions
      KVM: s390: Add capability for storage key extension of MEM_OP IOCTL
      KVM: s390: Update api documentation for memop ioctl
      KVM: s390: Clarify key argument for MEM_OP in api docs
      KVM: s390: Add missing vm MEM_OP size check

Thomas Huth (1):
      selftests: kvm: Check whether SIDA memop fails for normal guests

 Documentation/virt/kvm/api.rst            | 112 ++++++++++---
 MAINTAINERS                               |   2 +-
 arch/s390/include/asm/ctl_reg.h           |   2 +
 arch/s390/include/asm/page.h              |   2 +
 arch/s390/include/asm/uaccess.h           |  22 +++
 arch/s390/kvm/gaccess.c                   | 250 ++++++++++++++++++++++++++++--
 arch/s390/kvm/gaccess.h                   |  86 ++++++++--
 arch/s390/kvm/intercept.c                 |  12 +-
 arch/s390/kvm/kvm-s390.c                  | 132 +++++++++++++---
 arch/s390/kvm/priv.c                      |  66 ++++----
 arch/s390/lib/uaccess.c                   |  81 +++++++---
 include/uapi/linux/kvm.h                  |  11 +-
 tools/testing/selftests/kvm/.gitignore    |   1 +
 tools/testing/selftests/kvm/Makefile      |   1 +
 tools/testing/selftests/kvm/s390x/memop.c |  15 ++
 tools/testing/selftests/kvm/s390x/tprot.c | 227 +++++++++++++++++++++++++++
 16 files changed, 897 insertions(+), 125 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/s390x/tprot.c

[GIT PULL 01/13] KVM: s390: MAINTAINERS: promote Claudio Imbrenda

[Christian Borntraeger]

Claudio has volunteered to be more involved in the maintainership of
s390 KVM.

Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220210085310.26388-1-borntraeger@linux.ibm.com
---
 MAINTAINERS | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 3e461db9cd91..fe332650d032 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10547,8 +10547,8 @@ F:	arch/riscv/kvm/
 KERNEL VIRTUAL MACHINE for s390 (KVM/s390)
 M:	Christian Borntraeger <borntraeger@linux.ibm.com>
 M:	Janosch Frank <frankja@linux.ibm.com>
+M:	Claudio Imbrenda <imbrenda@linux.ibm.com>
 R:	David Hildenbrand <david@redhat.com>
-R:	Claudio Imbrenda <imbrenda@linux.ibm.com>
 L:	kvm@vger.kernel.org
 S:	Supported
 W:	http://www.ibm.com/developerworks/linux/linux390/
-- 
2.35.1

[GIT PULL 02/13] s390/uaccess: Add copy_from/to_user_key functions

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Add copy_from/to_user_key functions, which perform storage key checking.
These functions can be used by KVM for emulating instructions that need
to be key checked.
These functions differ from their non _key counterparts in
include/linux/uaccess.h only in the additional key argument and must be
kept in sync with those.

Since the existing uaccess implementation on s390 makes use of move
instructions that support having an additional access key supplied,
we can implement raw_copy_from/to_user_key by enhancing the
existing implementation.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-2-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 arch/s390/include/asm/uaccess.h | 22 +++++++++
 arch/s390/lib/uaccess.c         | 81 +++++++++++++++++++++++++--------
 2 files changed, 85 insertions(+), 18 deletions(-)

diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index d74e26b48604..ba1bcb91af95 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -44,6 +44,28 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n);
 #define INLINE_COPY_TO_USER
 #endif
 
+unsigned long __must_check
+_copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key);
+
+static __always_inline unsigned long __must_check
+copy_from_user_key(void *to, const void __user *from, unsigned long n, unsigned long key)
+{
+	if (likely(check_copy_size(to, n, false)))
+		n = _copy_from_user_key(to, from, n, key);
+	return n;
+}
+
+unsigned long __must_check
+_copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key);
+
+static __always_inline unsigned long __must_check
+copy_to_user_key(void __user *to, const void *from, unsigned long n, unsigned long key)
+{
+	if (likely(check_copy_size(from, n, true)))
+		n = _copy_to_user_key(to, from, n, key);
+	return n;
+}
+
 int __put_user_bad(void) __attribute__((noreturn));
 int __get_user_bad(void) __attribute__((noreturn));
 
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index 8a5d21461889..b709239feb5d 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -59,11 +59,13 @@ static inline int copy_with_mvcos(void)
 #endif
 
 static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr,
-						 unsigned long size)
+						 unsigned long size, unsigned long key)
 {
 	unsigned long tmp1, tmp2;
 	union oac spec = {
+		.oac2.key = key,
 		.oac2.as = PSW_BITS_AS_SECONDARY,
+		.oac2.k = 1,
 		.oac2.a = 1,
 	};
 
@@ -94,19 +96,19 @@ static inline unsigned long copy_from_user_mvcos(void *x, const void __user *ptr
 }
 
 static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
-						unsigned long size)
+						unsigned long size, unsigned long key)
 {
 	unsigned long tmp1, tmp2;
 
 	tmp1 = -256UL;
 	asm volatile(
 		"   sacf  0\n"
-		"0: mvcp  0(%0,%2),0(%1),%3\n"
+		"0: mvcp  0(%0,%2),0(%1),%[key]\n"
 		"7: jz    5f\n"
 		"1: algr  %0,%3\n"
 		"   la    %1,256(%1)\n"
 		"   la    %2,256(%2)\n"
-		"2: mvcp  0(%0,%2),0(%1),%3\n"
+		"2: mvcp  0(%0,%2),0(%1),%[key]\n"
 		"8: jnz   1b\n"
 		"   j     5f\n"
 		"3: la    %4,255(%1)\n"	/* %4 = ptr + 255 */
@@ -115,7 +117,7 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
 		"   slgr  %4,%1\n"
 		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
 		"   jnh   6f\n"
-		"4: mvcp  0(%4,%2),0(%1),%3\n"
+		"4: mvcp  0(%4,%2),0(%1),%[key]\n"
 		"9: slgr  %0,%4\n"
 		"   j     6f\n"
 		"5: slgr  %0,%0\n"
@@ -123,24 +125,49 @@ static inline unsigned long copy_from_user_mvcp(void *x, const void __user *ptr,
 		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
 		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
 		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
-		: : "cc", "memory");
+		: [key] "d" (key << 4)
+		: "cc", "memory");
 	return size;
 }
 
+static unsigned long raw_copy_from_user_key(void *to, const void __user *from,
+					    unsigned long n, unsigned long key)
+{
+	if (copy_with_mvcos())
+		return copy_from_user_mvcos(to, from, n, key);
+	return copy_from_user_mvcp(to, from, n, key);
+}
+
 unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
 {
-	if (copy_with_mvcos())
-		return copy_from_user_mvcos(to, from, n);
-	return copy_from_user_mvcp(to, from, n);
+	return raw_copy_from_user_key(to, from, n, 0);
 }
 EXPORT_SYMBOL(raw_copy_from_user);
 
+unsigned long _copy_from_user_key(void *to, const void __user *from,
+				  unsigned long n, unsigned long key)
+{
+	unsigned long res = n;
+
+	might_fault();
+	if (!should_fail_usercopy()) {
+		instrument_copy_from_user(to, from, n);
+		res = raw_copy_from_user_key(to, from, n, key);
+	}
+	if (unlikely(res))
+		memset(to + (n - res), 0, res);
+	return res;
+}
+EXPORT_SYMBOL(_copy_from_user_key);
+
 static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
-					       unsigned long size)
+					       unsigned long size, unsigned long key)
 {
 	unsigned long tmp1, tmp2;
 	union oac spec = {
+		.oac1.key = key,
 		.oac1.as = PSW_BITS_AS_SECONDARY,
+		.oac1.k = 1,
 		.oac1.a = 1,
 	};
 
@@ -171,19 +198,19 @@ static inline unsigned long copy_to_user_mvcos(void __user *ptr, const void *x,
 }
 
 static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
-					      unsigned long size)
+					      unsigned long size, unsigned long key)
 {
 	unsigned long tmp1, tmp2;
 
 	tmp1 = -256UL;
 	asm volatile(
 		"   sacf  0\n"
-		"0: mvcs  0(%0,%1),0(%2),%3\n"
+		"0: mvcs  0(%0,%1),0(%2),%[key]\n"
 		"7: jz    5f\n"
 		"1: algr  %0,%3\n"
 		"   la    %1,256(%1)\n"
 		"   la    %2,256(%2)\n"
-		"2: mvcs  0(%0,%1),0(%2),%3\n"
+		"2: mvcs  0(%0,%1),0(%2),%[key]\n"
 		"8: jnz   1b\n"
 		"   j     5f\n"
 		"3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
@@ -192,7 +219,7 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
 		"   slgr  %4,%1\n"
 		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
 		"   jnh   6f\n"
-		"4: mvcs  0(%4,%1),0(%2),%3\n"
+		"4: mvcs  0(%4,%1),0(%2),%[key]\n"
 		"9: slgr  %0,%4\n"
 		"   j     6f\n"
 		"5: slgr  %0,%0\n"
@@ -200,18 +227,36 @@ static inline unsigned long copy_to_user_mvcs(void __user *ptr, const void *x,
 		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
 		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
 		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
-		: : "cc", "memory");
+		: [key] "d" (key << 4)
+		: "cc", "memory");
 	return size;
 }
 
+static unsigned long raw_copy_to_user_key(void __user *to, const void *from,
+					  unsigned long n, unsigned long key)
+{
+	if (copy_with_mvcos())
+		return copy_to_user_mvcos(to, from, n, key);
+	return copy_to_user_mvcs(to, from, n, key);
+}
+
 unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 {
-	if (copy_with_mvcos())
-		return copy_to_user_mvcos(to, from, n);
-	return copy_to_user_mvcs(to, from, n);
+	return raw_copy_to_user_key(to, from, n, 0);
 }
 EXPORT_SYMBOL(raw_copy_to_user);
 
+unsigned long _copy_to_user_key(void __user *to, const void *from,
+				unsigned long n, unsigned long key)
+{
+	might_fault();
+	if (should_fail_usercopy())
+		return n;
+	instrument_copy_to_user(to, from, n);
+	return raw_copy_to_user_key(to, from, n, key);
+}
+EXPORT_SYMBOL(_copy_to_user_key);
+
 static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
 {
 	unsigned long tmp1, tmp2;
-- 
2.35.1

[GIT PULL 03/13] KVM: s390: Honor storage keys when accessing guest memory

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Storage key checking had not been implemented for instructions emulated
by KVM. Implement it by enhancing the functions used for guest access,
in particular those making use of access_guest which has been renamed
to access_guest_with_key.
Accesses via access_guest_real should not be key checked.

For actual accesses, key checking is done by
copy_from/to_user_key (which internally uses MVCOS/MVCP/MVCS).
In cases where accessibility is checked without an actual access,
this is performed by getting the storage key and checking if the access
key matches. In both cases, if applicable, storage and fetch protection
override are honored.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-3-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 arch/s390/include/asm/ctl_reg.h |   2 +
 arch/s390/include/asm/page.h    |   2 +
 arch/s390/kvm/gaccess.c         | 187 ++++++++++++++++++++++++++++++--
 arch/s390/kvm/gaccess.h         |  79 ++++++++++++--
 arch/s390/kvm/intercept.c       |  12 +-
 arch/s390/kvm/kvm-s390.c        |   4 +-
 6 files changed, 254 insertions(+), 32 deletions(-)

diff --git a/arch/s390/include/asm/ctl_reg.h b/arch/s390/include/asm/ctl_reg.h
index 04dc65f8901d..c800199a376b 100644
--- a/arch/s390/include/asm/ctl_reg.h
+++ b/arch/s390/include/asm/ctl_reg.h
@@ -12,6 +12,8 @@
 
 #define CR0_CLOCK_COMPARATOR_SIGN	BIT(63 - 10)
 #define CR0_LOW_ADDRESS_PROTECTION	BIT(63 - 35)
+#define CR0_FETCH_PROTECTION_OVERRIDE	BIT(63 - 38)
+#define CR0_STORAGE_PROTECTION_OVERRIDE	BIT(63 - 39)
 #define CR0_EMERGENCY_SIGNAL_SUBMASK	BIT(63 - 49)
 #define CR0_EXTERNAL_CALL_SUBMASK	BIT(63 - 50)
 #define CR0_CLOCK_COMPARATOR_SUBMASK	BIT(63 - 52)
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index d98d17a36c7b..cfc4d6fb2385 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -20,6 +20,8 @@
 #define PAGE_SIZE	_PAGE_SIZE
 #define PAGE_MASK	_PAGE_MASK
 #define PAGE_DEFAULT_ACC	0
+/* storage-protection override */
+#define PAGE_SPO_ACC		9
 #define PAGE_DEFAULT_KEY	(PAGE_DEFAULT_ACC << 4)
 
 #define HPAGE_SHIFT	20
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 4460808c3b9a..7fca0cff4c12 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -10,6 +10,7 @@
 #include <linux/mm_types.h>
 #include <linux/err.h>
 #include <linux/pgtable.h>
+#include <linux/bitfield.h>
 
 #include <asm/gmap.h>
 #include "kvm-s390.h"
@@ -794,6 +795,79 @@ static int low_address_protection_enabled(struct kvm_vcpu *vcpu,
 	return 1;
 }
 
+static bool fetch_prot_override_applicable(struct kvm_vcpu *vcpu, enum gacc_mode mode,
+					   union asce asce)
+{
+	psw_t *psw = &vcpu->arch.sie_block->gpsw;
+	unsigned long override;
+
+	if (mode == GACC_FETCH || mode == GACC_IFETCH) {
+		/* check if fetch protection override enabled */
+		override = vcpu->arch.sie_block->gcr[0];
+		override &= CR0_FETCH_PROTECTION_OVERRIDE;
+		/* not applicable if subject to DAT && private space */
+		override = override && !(psw_bits(*psw).dat && asce.p);
+		return override;
+	}
+	return false;
+}
+
+static bool fetch_prot_override_applies(unsigned long ga, unsigned int len)
+{
+	return ga < 2048 && ga + len <= 2048;
+}
+
+static bool storage_prot_override_applicable(struct kvm_vcpu *vcpu)
+{
+	/* check if storage protection override enabled */
+	return vcpu->arch.sie_block->gcr[0] & CR0_STORAGE_PROTECTION_OVERRIDE;
+}
+
+static bool storage_prot_override_applies(u8 access_control)
+{
+	/* matches special storage protection override key (9) -> allow */
+	return access_control == PAGE_SPO_ACC;
+}
+
+static int vcpu_check_access_key(struct kvm_vcpu *vcpu, u8 access_key,
+				 enum gacc_mode mode, union asce asce, gpa_t gpa,
+				 unsigned long ga, unsigned int len)
+{
+	u8 storage_key, access_control;
+	unsigned long hva;
+	int r;
+
+	/* access key 0 matches any storage key -> allow */
+	if (access_key == 0)
+		return 0;
+	/*
+	 * caller needs to ensure that gfn is accessible, so we can
+	 * assume that this cannot fail
+	 */
+	hva = gfn_to_hva(vcpu->kvm, gpa_to_gfn(gpa));
+	mmap_read_lock(current->mm);
+	r = get_guest_storage_key(current->mm, hva, &storage_key);
+	mmap_read_unlock(current->mm);
+	if (r)
+		return r;
+	access_control = FIELD_GET(_PAGE_ACC_BITS, storage_key);
+	/* access key matches storage key -> allow */
+	if (access_control == access_key)
+		return 0;
+	if (mode == GACC_FETCH || mode == GACC_IFETCH) {
+		/* it is a fetch and fetch protection is off -> allow */
+		if (!(storage_key & _PAGE_FP_BIT))
+			return 0;
+		if (fetch_prot_override_applicable(vcpu, mode, asce) &&
+		    fetch_prot_override_applies(ga, len))
+			return 0;
+	}
+	if (storage_prot_override_applicable(vcpu) &&
+	    storage_prot_override_applies(access_control))
+		return 0;
+	return PGM_PROTECTION;
+}
+
 /**
  * guest_range_to_gpas() - Calculate guest physical addresses of page fragments
  * covering a logical range
@@ -804,6 +878,7 @@ static int low_address_protection_enabled(struct kvm_vcpu *vcpu,
  * @len: length of range in bytes
  * @asce: address-space-control element to use for translation
  * @mode: access mode
+ * @access_key: access key to mach the range's storage keys against
  *
  * Translate a logical range to a series of guest absolute addresses,
  * such that the concatenation of page fragments starting at each gpa make up
@@ -830,7 +905,8 @@ static int low_address_protection_enabled(struct kvm_vcpu *vcpu,
  */
 static int guest_range_to_gpas(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
 			       unsigned long *gpas, unsigned long len,
-			       const union asce asce, enum gacc_mode mode)
+			       const union asce asce, enum gacc_mode mode,
+			       u8 access_key)
 {
 	psw_t *psw = &vcpu->arch.sie_block->gpsw;
 	unsigned int offset = offset_in_page(ga);
@@ -857,6 +933,10 @@ static int guest_range_to_gpas(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
 		}
 		if (rc)
 			return trans_exc(vcpu, rc, ga, ar, mode, prot);
+		rc = vcpu_check_access_key(vcpu, access_key, mode, asce, gpa, ga,
+					   fragment_len);
+		if (rc)
+			return trans_exc(vcpu, rc, ga, ar, mode, PROT_TYPE_KEYC);
 		if (gpas)
 			*gpas++ = gpa;
 		offset = 0;
@@ -880,16 +960,54 @@ static int access_guest_page(struct kvm *kvm, enum gacc_mode mode, gpa_t gpa,
 	return rc;
 }
 
-int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
-		 unsigned long len, enum gacc_mode mode)
+static int
+access_guest_page_with_key(struct kvm *kvm, enum gacc_mode mode, gpa_t gpa,
+			   void *data, unsigned int len, u8 access_key)
+{
+	struct kvm_memory_slot *slot;
+	bool writable;
+	gfn_t gfn;
+	hva_t hva;
+	int rc;
+
+	gfn = gpa >> PAGE_SHIFT;
+	slot = gfn_to_memslot(kvm, gfn);
+	hva = gfn_to_hva_memslot_prot(slot, gfn, &writable);
+
+	if (kvm_is_error_hva(hva))
+		return PGM_ADDRESSING;
+	/*
+	 * Check if it's a ro memslot, even tho that can't occur (they're unsupported).
+	 * Don't try to actually handle that case.
+	 */
+	if (!writable && mode == GACC_STORE)
+		return -EOPNOTSUPP;
+	hva += offset_in_page(gpa);
+	if (mode == GACC_STORE)
+		rc = copy_to_user_key((void __user *)hva, data, len, access_key);
+	else
+		rc = copy_from_user_key(data, (void __user *)hva, len, access_key);
+	if (rc)
+		return PGM_PROTECTION;
+	if (mode == GACC_STORE)
+		mark_page_dirty_in_slot(kvm, slot, gfn);
+	return 0;
+}
+
+int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
+			  void *data, unsigned long len, enum gacc_mode mode,
+			  u8 access_key)
 {
 	psw_t *psw = &vcpu->arch.sie_block->gpsw;
 	unsigned long nr_pages, idx;
 	unsigned long gpa_array[2];
 	unsigned int fragment_len;
 	unsigned long *gpas;
+	enum prot_type prot;
 	int need_ipte_lock;
 	union asce asce;
+	bool try_storage_prot_override;
+	bool try_fetch_prot_override;
 	int rc;
 
 	if (!len)
@@ -904,16 +1022,47 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
 		gpas = vmalloc(array_size(nr_pages, sizeof(unsigned long)));
 	if (!gpas)
 		return -ENOMEM;
+	try_fetch_prot_override = fetch_prot_override_applicable(vcpu, mode, asce);
+	try_storage_prot_override = storage_prot_override_applicable(vcpu);
 	need_ipte_lock = psw_bits(*psw).dat && !asce.r;
 	if (need_ipte_lock)
 		ipte_lock(vcpu);
-	rc = guest_range_to_gpas(vcpu, ga, ar, gpas, len, asce, mode);
-	for (idx = 0; idx < nr_pages && !rc; idx++) {
+	/*
+	 * Since we do the access further down ultimately via a move instruction
+	 * that does key checking and returns an error in case of a protection
+	 * violation, we don't need to do the check during address translation.
+	 * Skip it by passing access key 0, which matches any storage key,
+	 * obviating the need for any further checks. As a result the check is
+	 * handled entirely in hardware on access, we only need to take care to
+	 * forego key protection checking if fetch protection override applies or
+	 * retry with the special key 9 in case of storage protection override.
+	 */
+	rc = guest_range_to_gpas(vcpu, ga, ar, gpas, len, asce, mode, 0);
+	if (rc)
+		goto out_unlock;
+	for (idx = 0; idx < nr_pages; idx++) {
 		fragment_len = min(PAGE_SIZE - offset_in_page(gpas[idx]), len);
-		rc = access_guest_page(vcpu->kvm, mode, gpas[idx], data, fragment_len);
+		if (try_fetch_prot_override && fetch_prot_override_applies(ga, fragment_len)) {
+			rc = access_guest_page(vcpu->kvm, mode, gpas[idx],
+					       data, fragment_len);
+		} else {
+			rc = access_guest_page_with_key(vcpu->kvm, mode, gpas[idx],
+							data, fragment_len, access_key);
+		}
+		if (rc == PGM_PROTECTION && try_storage_prot_override)
+			rc = access_guest_page_with_key(vcpu->kvm, mode, gpas[idx],
+							data, fragment_len, PAGE_SPO_ACC);
+		if (rc == PGM_PROTECTION)
+			prot = PROT_TYPE_KEYC;
+		if (rc)
+			break;
 		len -= fragment_len;
 		data += fragment_len;
+		ga = kvm_s390_logical_to_effective(vcpu, ga + fragment_len);
 	}
+	if (rc > 0)
+		rc = trans_exc(vcpu, rc, ga, ar, mode, prot);
+out_unlock:
 	if (need_ipte_lock)
 		ipte_unlock(vcpu);
 	if (nr_pages > ARRAY_SIZE(gpa_array))
@@ -940,12 +1089,13 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
 }
 
 /**
- * guest_translate_address - translate guest logical into guest absolute address
+ * guest_translate_address_with_key - translate guest logical into guest absolute address
  * @vcpu: virtual cpu
  * @gva: Guest virtual address
  * @ar: Access register
  * @gpa: Guest physical address
  * @mode: Translation access mode
+ * @access_key: access key to mach the storage key with
  *
  * Parameter semantics are the same as the ones from guest_translate.
  * The memory contents at the guest address are not changed.
@@ -953,8 +1103,9 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
  * Note: The IPTE lock is not taken during this function, so the caller
  * has to take care of this.
  */
-int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
-			    unsigned long *gpa, enum gacc_mode mode)
+int guest_translate_address_with_key(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
+				     unsigned long *gpa, enum gacc_mode mode,
+				     u8 access_key)
 {
 	union asce asce;
 	int rc;
@@ -963,7 +1114,17 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
 	rc = get_vcpu_asce(vcpu, &asce, gva, ar, mode);
 	if (rc)
 		return rc;
-	return guest_range_to_gpas(vcpu, gva, ar, gpa, 1, asce, mode);
+	return guest_range_to_gpas(vcpu, gva, ar, gpa, 1, asce, mode,
+				   access_key);
+}
+
+int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
+			    unsigned long *gpa, enum gacc_mode mode)
+{
+	u8 access_key = psw_bits(vcpu->arch.sie_block->gpsw).key;
+
+	return guest_translate_address_with_key(vcpu, gva, ar, gpa, mode,
+						access_key);
 }
 
 /**
@@ -973,9 +1134,10 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
  * @ar: Access register
  * @length: Length of test range
  * @mode: Translation access mode
+ * @access_key: access key to mach the storage keys with
  */
 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
-		    unsigned long length, enum gacc_mode mode)
+		    unsigned long length, enum gacc_mode mode, u8 access_key)
 {
 	union asce asce;
 	int rc = 0;
@@ -984,7 +1146,8 @@ int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
 	if (rc)
 		return rc;
 	ipte_lock(vcpu);
-	rc = guest_range_to_gpas(vcpu, gva, ar, NULL, length, asce, mode);
+	rc = guest_range_to_gpas(vcpu, gva, ar, NULL, length, asce, mode,
+				 access_key);
 	ipte_unlock(vcpu);
 
 	return rc;
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index 7c72a5e3449f..e5b2f56e7962 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -186,24 +186,31 @@ enum gacc_mode {
 	GACC_IFETCH,
 };
 
+int guest_translate_address_with_key(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
+				     unsigned long *gpa, enum gacc_mode mode,
+				     u8 access_key);
+
 int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva,
 			    u8 ar, unsigned long *gpa, enum gacc_mode mode);
-int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
-		    unsigned long length, enum gacc_mode mode);
 
-int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
-		 unsigned long len, enum gacc_mode mode);
+int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
+		    unsigned long length, enum gacc_mode mode, u8 access_key);
+
+int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
+			  void *data, unsigned long len, enum gacc_mode mode,
+			  u8 access_key);
 
 int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
 		      void *data, unsigned long len, enum gacc_mode mode);
 
 /**
- * write_guest - copy data from kernel space to guest space
+ * write_guest_with_key - copy data from kernel space to guest space
  * @vcpu: virtual cpu
  * @ga: guest address
  * @ar: access register
  * @data: source address in kernel space
  * @len: number of bytes to copy
+ * @access_key: access key the storage key needs to match
  *
  * Copy @len bytes from @data (kernel space) to @ga (guest address).
  * In order to copy data to guest space the PSW of the vcpu is inspected:
@@ -214,8 +221,8 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
  * The addressing mode of the PSW is also inspected, so that address wrap
  * around is taken into account for 24-, 31- and 64-bit addressing mode,
  * if the to be copied data crosses page boundaries in guest address space.
- * In addition also low address and DAT protection are inspected before
- * copying any data (key protection is currently not implemented).
+ * In addition low address, DAT and key protection checks are performed before
+ * copying any data.
  *
  * This function modifies the 'struct kvm_s390_pgm_info pgm' member of @vcpu.
  * In case of an access exception (e.g. protection exception) pgm will contain
@@ -243,10 +250,53 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
  *	 if data has been changed in guest space in case of an exception.
  */
 static inline __must_check
+int write_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
+			 void *data, unsigned long len, u8 access_key)
+{
+	return access_guest_with_key(vcpu, ga, ar, data, len, GACC_STORE,
+				     access_key);
+}
+
+/**
+ * write_guest - copy data from kernel space to guest space
+ * @vcpu: virtual cpu
+ * @ga: guest address
+ * @ar: access register
+ * @data: source address in kernel space
+ * @len: number of bytes to copy
+ *
+ * The behaviour of write_guest is identical to write_guest_with_key, except
+ * that the PSW access key is used instead of an explicit argument.
+ */
+static inline __must_check
 int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
 		unsigned long len)
 {
-	return access_guest(vcpu, ga, ar, data, len, GACC_STORE);
+	u8 access_key = psw_bits(vcpu->arch.sie_block->gpsw).key;
+
+	return write_guest_with_key(vcpu, ga, ar, data, len, access_key);
+}
+
+/**
+ * read_guest_with_key - copy data from guest space to kernel space
+ * @vcpu: virtual cpu
+ * @ga: guest address
+ * @ar: access register
+ * @data: destination address in kernel space
+ * @len: number of bytes to copy
+ * @access_key: access key the storage key needs to match
+ *
+ * Copy @len bytes from @ga (guest address) to @data (kernel space).
+ *
+ * The behaviour of read_guest_with_key is identical to write_guest_with_key,
+ * except that data will be copied from guest space to kernel space.
+ */
+static inline __must_check
+int read_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
+			void *data, unsigned long len, u8 access_key)
+{
+	return access_guest_with_key(vcpu, ga, ar, data, len, GACC_FETCH,
+				     access_key);
 }
 
 /**
@@ -259,14 +309,16 @@ int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
  *
  * Copy @len bytes from @ga (guest address) to @data (kernel space).
  *
- * The behaviour of read_guest is identical to write_guest, except that
- * data will be copied from guest space to kernel space.
+ * The behaviour of read_guest is identical to read_guest_with_key, except
+ * that the PSW access key is used instead of an explicit argument.
  */
 static inline __must_check
 int read_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
 	       unsigned long len)
 {
-	return access_guest(vcpu, ga, ar, data, len, GACC_FETCH);
+	u8 access_key = psw_bits(vcpu->arch.sie_block->gpsw).key;
+
+	return read_guest_with_key(vcpu, ga, ar, data, len, access_key);
 }
 
 /**
@@ -287,7 +339,10 @@ static inline __must_check
 int read_guest_instr(struct kvm_vcpu *vcpu, unsigned long ga, void *data,
 		     unsigned long len)
 {
-	return access_guest(vcpu, ga, 0, data, len, GACC_IFETCH);
+	u8 access_key = psw_bits(vcpu->arch.sie_block->gpsw).key;
+
+	return access_guest_with_key(vcpu, ga, 0, data, len, GACC_IFETCH,
+				     access_key);
 }
 
 /**
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index d07ff646d844..8bd42a20d924 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -331,18 +331,18 @@ static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 
 	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 
-	/* Make sure that the source is paged-in */
-	rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
-				     reg2, &srcaddr, GACC_FETCH);
+	/* Ensure that the source is paged-in, no actual access -> no key checking */
+	rc = guest_translate_address_with_key(vcpu, vcpu->run->s.regs.gprs[reg2],
+					      reg2, &srcaddr, GACC_FETCH, 0);
 	if (rc)
 		return kvm_s390_inject_prog_cond(vcpu, rc);
 	rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 	if (rc != 0)
 		return rc;
 
-	/* Make sure that the destination is paged-in */
-	rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
-				     reg1, &dstaddr, GACC_STORE);
+	/* Ensure that the source is paged-in, no actual access -> no key checking */
+	rc = guest_translate_address_with_key(vcpu, vcpu->run->s.regs.gprs[reg1],
+					      reg1, &dstaddr, GACC_STORE, 0);
 	if (rc)
 		return kvm_s390_inject_prog_cond(vcpu, rc);
 	rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 2296b1ff1e02..fdbd6c1dc709 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4713,7 +4713,7 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 	case KVM_S390_MEMOP_LOGICAL_READ:
 		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
 			r = check_gva_range(vcpu, mop->gaddr, mop->ar,
-					    mop->size, GACC_FETCH);
+					    mop->size, GACC_FETCH, 0);
 			break;
 		}
 		r = read_guest(vcpu, mop->gaddr, mop->ar, tmpbuf, mop->size);
@@ -4725,7 +4725,7 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 	case KVM_S390_MEMOP_LOGICAL_WRITE:
 		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
 			r = check_gva_range(vcpu, mop->gaddr, mop->ar,
-					    mop->size, GACC_STORE);
+					    mop->size, GACC_STORE, 0);
 			break;
 		}
 		if (copy_from_user(tmpbuf, uaddr, mop->size)) {
-- 
2.35.1

[GIT PULL 04/13] KVM: s390: handle_tprot: Honor storage keys

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Use the access key operand to check for key protection when
translating guest addresses.
Since the translation code checks for accessing exceptions/error hvas,
we can remove the check here and simplify the control flow.
Keep checking if the memory is read-only even if such memslots are
currently not supported.

handle_tprot was the last user of guest_translate_address,
so remove it.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-4-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 arch/s390/kvm/gaccess.c |  9 ------
 arch/s390/kvm/gaccess.h |  3 --
 arch/s390/kvm/priv.c    | 66 ++++++++++++++++++++++-------------------
 3 files changed, 35 insertions(+), 43 deletions(-)

diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 7fca0cff4c12..37838f637707 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -1118,15 +1118,6 @@ int guest_translate_address_with_key(struct kvm_vcpu *vcpu, unsigned long gva, u
 				   access_key);
 }
 
-int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
-			    unsigned long *gpa, enum gacc_mode mode)
-{
-	u8 access_key = psw_bits(vcpu->arch.sie_block->gpsw).key;
-
-	return guest_translate_address_with_key(vcpu, gva, ar, gpa, mode,
-						access_key);
-}
-
 /**
  * check_gva_range - test a range of guest virtual addresses for accessibility
  * @vcpu: virtual cpu
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index e5b2f56e7962..c5f2e7311b17 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -190,9 +190,6 @@ int guest_translate_address_with_key(struct kvm_vcpu *vcpu, unsigned long gva, u
 				     unsigned long *gpa, enum gacc_mode mode,
 				     u8 access_key);
 
-int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva,
-			    u8 ar, unsigned long *gpa, enum gacc_mode mode);
-
 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
 		    unsigned long length, enum gacc_mode mode, u8 access_key);
 
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 417154b314a6..30b24c42ef99 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -1443,10 +1443,11 @@ int kvm_s390_handle_eb(struct kvm_vcpu *vcpu)
 
 static int handle_tprot(struct kvm_vcpu *vcpu)
 {
-	u64 address1, address2;
-	unsigned long hva, gpa;
-	int ret = 0, cc = 0;
+	u64 address, operand2;
+	unsigned long gpa;
+	u8 access_key;
 	bool writable;
+	int ret, cc;
 	u8 ar;
 
 	vcpu->stat.instruction_tprot++;
@@ -1454,43 +1455,46 @@ static int handle_tprot(struct kvm_vcpu *vcpu)
 	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 		return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 
-	kvm_s390_get_base_disp_sse(vcpu, &address1, &address2, &ar, NULL);
+	kvm_s390_get_base_disp_sse(vcpu, &address, &operand2, &ar, NULL);
+	access_key = (operand2 & 0xf0) >> 4;
 
-	/* we only handle the Linux memory detection case:
-	 * access key == 0
-	 * everything else goes to userspace. */
-	if (address2 & 0xf0)
-		return -EOPNOTSUPP;
 	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
 		ipte_lock(vcpu);
-	ret = guest_translate_address(vcpu, address1, ar, &gpa, GACC_STORE);
-	if (ret == PGM_PROTECTION) {
+
+	ret = guest_translate_address_with_key(vcpu, address, ar, &gpa,
+					       GACC_STORE, access_key);
+	if (ret == 0) {
+		gfn_to_hva_prot(vcpu->kvm, gpa_to_gfn(gpa), &writable);
+	} else if (ret == PGM_PROTECTION) {
+		writable = false;
 		/* Write protected? Try again with read-only... */
-		cc = 1;
-		ret = guest_translate_address(vcpu, address1, ar, &gpa,
-					      GACC_FETCH);
+		ret = guest_translate_address_with_key(vcpu, address, ar, &gpa,
+						       GACC_FETCH, access_key);
 	}
-	if (ret) {
-		if (ret == PGM_ADDRESSING || ret == PGM_TRANSLATION_SPEC) {
-			ret = kvm_s390_inject_program_int(vcpu, ret);
-		} else if (ret > 0) {
-			/* Translation not available */
-			kvm_s390_set_psw_cc(vcpu, 3);
+	if (ret >= 0) {
+		cc = -1;
+
+		/* Fetching permitted; storing permitted */
+		if (ret == 0 && writable)
+			cc = 0;
+		/* Fetching permitted; storing not permitted */
+		else if (ret == 0 && !writable)
+			cc = 1;
+		/* Fetching not permitted; storing not permitted */
+		else if (ret == PGM_PROTECTION)
+			cc = 2;
+		/* Translation not available */
+		else if (ret != PGM_ADDRESSING && ret != PGM_TRANSLATION_SPEC)
+			cc = 3;
+
+		if (cc != -1) {
+			kvm_s390_set_psw_cc(vcpu, cc);
 			ret = 0;
+		} else {
+			ret = kvm_s390_inject_program_int(vcpu, ret);
 		}
-		goto out_unlock;
 	}
 
-	hva = gfn_to_hva_prot(vcpu->kvm, gpa_to_gfn(gpa), &writable);
-	if (kvm_is_error_hva(hva)) {
-		ret = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
-	} else {
-		if (!writable)
-			cc = 1;		/* Write not permitted ==> read-only */
-		kvm_s390_set_psw_cc(vcpu, cc);
-		/* Note: CC2 only occurs for storage keys (not supported yet) */
-	}
-out_unlock:
 	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
 		ipte_unlock(vcpu);
 	return ret;
-- 
2.35.1

[GIT PULL 05/13] KVM: s390: selftests: Test TEST PROTECTION emulation

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Test the emulation of TEST PROTECTION in the presence of storage keys.
Emulation only occurs under certain conditions, one of which is the host
page being protected.
Trigger this by protecting the test pages via mprotect.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-5-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 tools/testing/selftests/kvm/.gitignore    |   1 +
 tools/testing/selftests/kvm/Makefile      |   1 +
 tools/testing/selftests/kvm/s390x/tprot.c | 227 ++++++++++++++++++++++
 3 files changed, 229 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/s390x/tprot.c

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index dce7de7755e6..7903580a48ac 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -8,6 +8,7 @@
 /s390x/memop
 /s390x/resets
 /s390x/sync_regs_test
+/s390x/tprot
 /x86_64/amx_test
 /x86_64/cpuid_test
 /x86_64/cr4_cpuid_sync_test
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 0e4926bc9a58..086f490e808d 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -121,6 +121,7 @@ TEST_GEN_PROGS_aarch64 += kvm_binary_stats_test
 TEST_GEN_PROGS_s390x = s390x/memop
 TEST_GEN_PROGS_s390x += s390x/resets
 TEST_GEN_PROGS_s390x += s390x/sync_regs_test
+TEST_GEN_PROGS_s390x += s390x/tprot
 TEST_GEN_PROGS_s390x += demand_paging_test
 TEST_GEN_PROGS_s390x += dirty_log_test
 TEST_GEN_PROGS_s390x += kvm_create_max_vcpus
diff --git a/tools/testing/selftests/kvm/s390x/tprot.c b/tools/testing/selftests/kvm/s390x/tprot.c
new file mode 100644
index 000000000000..c097b9db495e
--- /dev/null
+++ b/tools/testing/selftests/kvm/s390x/tprot.c
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Test TEST PROTECTION emulation.
+ *
+ * Copyright IBM Corp. 2021
+ */
+
+#include <sys/mman.h>
+#include "test_util.h"
+#include "kvm_util.h"
+
+#define PAGE_SHIFT 12
+#define PAGE_SIZE (1 << PAGE_SHIFT)
+#define CR0_FETCH_PROTECTION_OVERRIDE	(1UL << (63 - 38))
+#define CR0_STORAGE_PROTECTION_OVERRIDE	(1UL << (63 - 39))
+
+#define VCPU_ID 1
+
+static __aligned(PAGE_SIZE) uint8_t pages[2][PAGE_SIZE];
+static uint8_t *const page_store_prot = pages[0];
+static uint8_t *const page_fetch_prot = pages[1];
+
+/* Nonzero return value indicates that address not mapped */
+static int set_storage_key(void *addr, uint8_t key)
+{
+	int not_mapped = 0;
+
+	asm volatile (
+		       "lra	%[addr], 0(0,%[addr])\n"
+		"	jz	0f\n"
+		"	llill	%[not_mapped],1\n"
+		"	j	1f\n"
+		"0:	sske	%[key], %[addr]\n"
+		"1:"
+		: [addr] "+&a" (addr), [not_mapped] "+r" (not_mapped)
+		: [key] "r" (key)
+		: "cc"
+	);
+	return -not_mapped;
+}
+
+enum permission {
+	READ_WRITE = 0,
+	READ = 1,
+	RW_PROTECTED = 2,
+	TRANSL_UNAVAIL = 3,
+};
+
+static enum permission test_protection(void *addr, uint8_t key)
+{
+	uint64_t mask;
+
+	asm volatile (
+		       "tprot	%[addr], 0(%[key])\n"
+		"	ipm	%[mask]\n"
+		: [mask] "=r" (mask)
+		: [addr] "Q" (*(char *)addr),
+		  [key] "a" (key)
+		: "cc"
+	);
+
+	return (enum permission)(mask >> 28);
+}
+
+enum stage {
+	STAGE_END,
+	STAGE_INIT_SIMPLE,
+	TEST_SIMPLE,
+	STAGE_INIT_FETCH_PROT_OVERRIDE,
+	TEST_FETCH_PROT_OVERRIDE,
+	TEST_STORAGE_PROT_OVERRIDE,
+};
+
+struct test {
+	enum stage stage;
+	void *addr;
+	uint8_t key;
+	enum permission expected;
+} tests[] = {
+	/*
+	 * We perform each test in the array by executing TEST PROTECTION on
+	 * the specified addr with the specified key and checking if the returned
+	 * permissions match the expected value.
+	 * Both guest and host cooperate to set up the required test conditions.
+	 * A central condition is that the page targeted by addr has to be DAT
+	 * protected in the host mappings, in order for KVM to emulate the
+	 * TEST PROTECTION instruction.
+	 * Since the page tables are shared, the host uses mprotect to achieve
+	 * this.
+	 *
+	 * Test resulting in RW_PROTECTED/TRANSL_UNAVAIL will be interpreted
+	 * by SIE, not KVM, but there is no harm in testing them also.
+	 * See Enhanced Suppression-on-Protection Facilities in the
+	 * Interpretive-Execution Mode
+	 */
+	/*
+	 * guest: set storage key of page_store_prot to 1
+	 *        storage key of page_fetch_prot to 9 and enable
+	 *        protection for it
+	 * STAGE_INIT_SIMPLE
+	 * host: write protect both via mprotect
+	 */
+	/* access key 0 matches any storage key -> RW */
+	{ TEST_SIMPLE, page_store_prot, 0x00, READ_WRITE },
+	/* access key matches storage key -> RW */
+	{ TEST_SIMPLE, page_store_prot, 0x10, READ_WRITE },
+	/* mismatched keys, but no fetch protection -> RO */
+	{ TEST_SIMPLE, page_store_prot, 0x20, READ },
+	/* access key 0 matches any storage key -> RW */
+	{ TEST_SIMPLE, page_fetch_prot, 0x00, READ_WRITE },
+	/* access key matches storage key -> RW */
+	{ TEST_SIMPLE, page_fetch_prot, 0x90, READ_WRITE },
+	/* mismatched keys, fetch protection -> inaccessible */
+	{ TEST_SIMPLE, page_fetch_prot, 0x10, RW_PROTECTED },
+	/* page 0 not mapped yet -> translation not available */
+	{ TEST_SIMPLE, (void *)0x00, 0x10, TRANSL_UNAVAIL },
+	/*
+	 * host: try to map page 0
+	 * guest: set storage key of page 0 to 9 and enable fetch protection
+	 * STAGE_INIT_FETCH_PROT_OVERRIDE
+	 * host: write protect page 0
+	 *       enable fetch protection override
+	 */
+	/* mismatched keys, fetch protection, but override applies -> RO */
+	{ TEST_FETCH_PROT_OVERRIDE, (void *)0x00, 0x10, READ },
+	/* mismatched keys, fetch protection, override applies to 0-2048 only -> inaccessible */
+	{ TEST_FETCH_PROT_OVERRIDE, (void *)2049, 0x10, RW_PROTECTED },
+	/*
+	 * host: enable storage protection override
+	 */
+	/* mismatched keys, but override applies (storage key 9) -> RW */
+	{ TEST_STORAGE_PROT_OVERRIDE, page_fetch_prot, 0x10, READ_WRITE },
+	/* mismatched keys, no fetch protection, override doesn't apply -> RO */
+	{ TEST_STORAGE_PROT_OVERRIDE, page_store_prot, 0x20, READ },
+	/* mismatched keys, but override applies (storage key 9) -> RW */
+	{ TEST_STORAGE_PROT_OVERRIDE, (void *)2049, 0x10, READ_WRITE },
+	/* end marker */
+	{ STAGE_END, 0, 0, 0 },
+};
+
+static enum stage perform_next_stage(int *i, bool mapped_0)
+{
+	enum stage stage = tests[*i].stage;
+	enum permission result;
+	bool skip;
+
+	for (; tests[*i].stage == stage; (*i)++) {
+		/*
+		 * Some fetch protection override tests require that page 0
+		 * be mapped, however, when the hosts tries to map that page via
+		 * vm_vaddr_alloc, it may happen that some other page gets mapped
+		 * instead.
+		 * In order to skip these tests we detect this inside the guest
+		 */
+		skip = tests[*i].addr < (void *)4096 &&
+		       tests[*i].expected != TRANSL_UNAVAIL &&
+		       !mapped_0;
+		if (!skip) {
+			result = test_protection(tests[*i].addr, tests[*i].key);
+			GUEST_ASSERT_2(result == tests[*i].expected, *i, result);
+		}
+	}
+	return stage;
+}
+
+static void guest_code(void)
+{
+	bool mapped_0;
+	int i = 0;
+
+	GUEST_ASSERT_EQ(set_storage_key(page_store_prot, 0x10), 0);
+	GUEST_ASSERT_EQ(set_storage_key(page_fetch_prot, 0x98), 0);
+	GUEST_SYNC(STAGE_INIT_SIMPLE);
+	GUEST_SYNC(perform_next_stage(&i, false));
+
+	/* Fetch-protection override */
+	mapped_0 = !set_storage_key((void *)0, 0x98);
+	GUEST_SYNC(STAGE_INIT_FETCH_PROT_OVERRIDE);
+	GUEST_SYNC(perform_next_stage(&i, mapped_0));
+
+	/* Storage-protection override */
+	GUEST_SYNC(perform_next_stage(&i, mapped_0));
+}
+
+#define HOST_SYNC(vmp, stage)							\
+({										\
+	struct kvm_vm *__vm = (vmp);						\
+	struct ucall uc;							\
+	int __stage = (stage);							\
+										\
+	vcpu_run(__vm, VCPU_ID);						\
+	get_ucall(__vm, VCPU_ID, &uc);						\
+	if (uc.cmd == UCALL_ABORT) {						\
+		TEST_FAIL("line %lu: %s, hints: %lu, %lu", uc.args[1],		\
+			  (const char *)uc.args[0], uc.args[2], uc.args[3]);	\
+	}									\
+	ASSERT_EQ(uc.cmd, UCALL_SYNC);						\
+	ASSERT_EQ(uc.args[1], __stage);						\
+})
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vm *vm;
+	struct kvm_run *run;
+	vm_vaddr_t guest_0_page;
+
+	vm = vm_create_default(VCPU_ID, 0, guest_code);
+	run = vcpu_state(vm, VCPU_ID);
+
+	HOST_SYNC(vm, STAGE_INIT_SIMPLE);
+	mprotect(addr_gva2hva(vm, (vm_vaddr_t)pages), PAGE_SIZE * 2, PROT_READ);
+	HOST_SYNC(vm, TEST_SIMPLE);
+
+	guest_0_page = vm_vaddr_alloc(vm, PAGE_SIZE, 0);
+	if (guest_0_page != 0)
+		print_skip("Did not allocate page at 0 for fetch protection override tests");
+	HOST_SYNC(vm, STAGE_INIT_FETCH_PROT_OVERRIDE);
+	if (guest_0_page == 0)
+		mprotect(addr_gva2hva(vm, (vm_vaddr_t)0), PAGE_SIZE, PROT_READ);
+	run->s.regs.crs[0] |= CR0_FETCH_PROTECTION_OVERRIDE;
+	run->kvm_dirty_regs = KVM_SYNC_CRS;
+	HOST_SYNC(vm, TEST_FETCH_PROT_OVERRIDE);
+
+	run->s.regs.crs[0] |= CR0_STORAGE_PROTECTION_OVERRIDE;
+	run->kvm_dirty_regs = KVM_SYNC_CRS;
+	HOST_SYNC(vm, TEST_STORAGE_PROT_OVERRIDE);
+}
-- 
2.35.1

[GIT PULL 06/13] KVM: s390: Add optional storage key checking to MEMOP IOCTL

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

User space needs a mechanism to perform key checked accesses when
emulating instructions.

The key can be passed as an additional argument.
Having an additional argument is flexible, as user space can
pass the guest PSW's key, in order to make an access the same way the
CPU would, or pass another key if necessary.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-6-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 31 +++++++++++++++++++++----------
 include/uapi/linux/kvm.h |  6 +++++-
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index fdbd6c1dc709..c31b40abfa23 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2359,6 +2359,11 @@ static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
 	return r;
 }
 
+static bool access_key_invalid(u8 access_key)
+{
+	return access_key > 0xf;
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {
@@ -4692,17 +4697,21 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 	void *tmpbuf = NULL;
 	int r = 0;
 	const u64 supported_flags = KVM_S390_MEMOP_F_INJECT_EXCEPTION
-				    | KVM_S390_MEMOP_F_CHECK_ONLY;
+				    | KVM_S390_MEMOP_F_CHECK_ONLY
+				    | KVM_S390_MEMOP_F_SKEY_PROTECTION;
 
 	if (mop->flags & ~supported_flags || mop->ar >= NUM_ACRS || !mop->size)
 		return -EINVAL;
-
 	if (mop->size > MEM_OP_MAX_SIZE)
 		return -E2BIG;
-
 	if (kvm_s390_pv_cpu_is_protected(vcpu))
 		return -EINVAL;
-
+	if (mop->flags & KVM_S390_MEMOP_F_SKEY_PROTECTION) {
+		if (access_key_invalid(mop->key))
+			return -EINVAL;
+	} else {
+		mop->key = 0;
+	}
 	if (!(mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY)) {
 		tmpbuf = vmalloc(mop->size);
 		if (!tmpbuf)
@@ -4712,11 +4721,12 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 	switch (mop->op) {
 	case KVM_S390_MEMOP_LOGICAL_READ:
 		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
-			r = check_gva_range(vcpu, mop->gaddr, mop->ar,
-					    mop->size, GACC_FETCH, 0);
+			r = check_gva_range(vcpu, mop->gaddr, mop->ar, mop->size,
+					    GACC_FETCH, mop->key);
 			break;
 		}
-		r = read_guest(vcpu, mop->gaddr, mop->ar, tmpbuf, mop->size);
+		r = read_guest_with_key(vcpu, mop->gaddr, mop->ar, tmpbuf,
+					mop->size, mop->key);
 		if (r == 0) {
 			if (copy_to_user(uaddr, tmpbuf, mop->size))
 				r = -EFAULT;
@@ -4724,15 +4734,16 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 		break;
 	case KVM_S390_MEMOP_LOGICAL_WRITE:
 		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
-			r = check_gva_range(vcpu, mop->gaddr, mop->ar,
-					    mop->size, GACC_STORE, 0);
+			r = check_gva_range(vcpu, mop->gaddr, mop->ar, mop->size,
+					    GACC_STORE, mop->key);
 			break;
 		}
 		if (copy_from_user(tmpbuf, uaddr, mop->size)) {
 			r = -EFAULT;
 			break;
 		}
-		r = write_guest(vcpu, mop->gaddr, mop->ar, tmpbuf, mop->size);
+		r = write_guest_with_key(vcpu, mop->gaddr, mop->ar, tmpbuf,
+					 mop->size, mop->key);
 		break;
 	}
 
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 5191b57e1562..4566f429db2c 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -562,7 +562,10 @@ struct kvm_s390_mem_op {
 	__u32 op;		/* type of operation */
 	__u64 buf;		/* buffer in userspace */
 	union {
-		__u8 ar;	/* the access register number */
+		struct {
+			__u8 ar;	/* the access register number */
+			__u8 key;	/* access key, ignored if flag unset */
+		};
 		__u32 sida_offset; /* offset into the sida */
 		__u8 reserved[32]; /* should be set to 0 */
 	};
@@ -575,6 +578,7 @@ struct kvm_s390_mem_op {
 /* flags for kvm_s390_mem_op->flags */
 #define KVM_S390_MEMOP_F_CHECK_ONLY		(1ULL << 0)
 #define KVM_S390_MEMOP_F_INJECT_EXCEPTION	(1ULL << 1)
+#define KVM_S390_MEMOP_F_SKEY_PROTECTION	(1ULL << 2)
 
 /* for KVM_INTERRUPT */
 struct kvm_interrupt {
-- 
2.35.1

[GIT PULL 07/13] KVM: s390: Add vm IOCTL for key checked guest absolute memory access

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Channel I/O honors storage keys and is performed on absolute memory.
For I/O emulation user space therefore needs to be able to do key
checked accesses.
The vm IOCTL supports read/write accesses, as well as checking
if an access would succeed.
Unlike relying on KVM_S390_GET_SKEYS for key checking would,
the vm IOCTL performs the check in lockstep with the read or write,
by, ultimately, mapping the access to move instructions that
support key protection checking with a supplied key.
Fetch and storage protection override are not applicable to absolute
accesses and so are not applied as they are when using the vcpu memop.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-7-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 arch/s390/kvm/gaccess.c  | 72 +++++++++++++++++++++++++++++++++++
 arch/s390/kvm/gaccess.h  |  6 +++
 arch/s390/kvm/kvm-s390.c | 81 ++++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/kvm.h |  2 +
 4 files changed, 161 insertions(+)

diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 37838f637707..d53a183c2005 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -795,6 +795,35 @@ static int low_address_protection_enabled(struct kvm_vcpu *vcpu,
 	return 1;
 }
 
+static int vm_check_access_key(struct kvm *kvm, u8 access_key,
+			       enum gacc_mode mode, gpa_t gpa)
+{
+	u8 storage_key, access_control;
+	bool fetch_protected;
+	unsigned long hva;
+	int r;
+
+	if (access_key == 0)
+		return 0;
+
+	hva = gfn_to_hva(kvm, gpa_to_gfn(gpa));
+	if (kvm_is_error_hva(hva))
+		return PGM_ADDRESSING;
+
+	mmap_read_lock(current->mm);
+	r = get_guest_storage_key(current->mm, hva, &storage_key);
+	mmap_read_unlock(current->mm);
+	if (r)
+		return r;
+	access_control = FIELD_GET(_PAGE_ACC_BITS, storage_key);
+	if (access_control == access_key)
+		return 0;
+	fetch_protected = storage_key & _PAGE_FP_BIT;
+	if ((mode == GACC_FETCH || mode == GACC_IFETCH) && !fetch_protected)
+		return 0;
+	return PGM_PROTECTION;
+}
+
 static bool fetch_prot_override_applicable(struct kvm_vcpu *vcpu, enum gacc_mode mode,
 					   union asce asce)
 {
@@ -994,6 +1023,26 @@ access_guest_page_with_key(struct kvm *kvm, enum gacc_mode mode, gpa_t gpa,
 	return 0;
 }
 
+int access_guest_abs_with_key(struct kvm *kvm, gpa_t gpa, void *data,
+			      unsigned long len, enum gacc_mode mode, u8 access_key)
+{
+	int offset = offset_in_page(gpa);
+	int fragment_len;
+	int rc;
+
+	while (min(PAGE_SIZE - offset, len) > 0) {
+		fragment_len = min(PAGE_SIZE - offset, len);
+		rc = access_guest_page_with_key(kvm, mode, gpa, data, fragment_len, access_key);
+		if (rc)
+			return rc;
+		offset = 0;
+		len -= fragment_len;
+		data += fragment_len;
+		gpa += fragment_len;
+	}
+	return 0;
+}
+
 int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
 			  void *data, unsigned long len, enum gacc_mode mode,
 			  u8 access_key)
@@ -1144,6 +1193,29 @@ int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
 	return rc;
 }
 
+/**
+ * check_gpa_range - test a range of guest physical addresses for accessibility
+ * @kvm: virtual machine instance
+ * @gpa: guest physical address
+ * @length: length of test range
+ * @mode: access mode to test, relevant for storage keys
+ * @access_key: access key to mach the storage keys with
+ */
+int check_gpa_range(struct kvm *kvm, unsigned long gpa, unsigned long length,
+		    enum gacc_mode mode, u8 access_key)
+{
+	unsigned int fragment_len;
+	int rc = 0;
+
+	while (length && !rc) {
+		fragment_len = min(PAGE_SIZE - offset_in_page(gpa), length);
+		rc = vm_check_access_key(kvm, access_key, mode, gpa);
+		length -= fragment_len;
+		gpa += fragment_len;
+	}
+	return rc;
+}
+
 /**
  * kvm_s390_check_low_addr_prot_real - check for low-address protection
  * @vcpu: virtual cpu
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index c5f2e7311b17..1124ff282012 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -193,6 +193,12 @@ int guest_translate_address_with_key(struct kvm_vcpu *vcpu, unsigned long gva, u
 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
 		    unsigned long length, enum gacc_mode mode, u8 access_key);
 
+int check_gpa_range(struct kvm *kvm, unsigned long gpa, unsigned long length,
+		    enum gacc_mode mode, u8 access_key);
+
+int access_guest_abs_with_key(struct kvm *kvm, gpa_t gpa, void *data,
+			      unsigned long len, enum gacc_mode mode, u8 access_key);
+
 int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
 			  void *data, unsigned long len, enum gacc_mode mode,
 			  u8 access_key);
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index c31b40abfa23..36bc73b5f5de 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2364,6 +2364,78 @@ static bool access_key_invalid(u8 access_key)
 	return access_key > 0xf;
 }
 
+static int kvm_s390_vm_mem_op(struct kvm *kvm, struct kvm_s390_mem_op *mop)
+{
+	void __user *uaddr = (void __user *)mop->buf;
+	u64 supported_flags;
+	void *tmpbuf = NULL;
+	int r, srcu_idx;
+
+	supported_flags = KVM_S390_MEMOP_F_SKEY_PROTECTION
+			  | KVM_S390_MEMOP_F_CHECK_ONLY;
+	if (mop->flags & ~supported_flags)
+		return -EINVAL;
+	if (mop->size > MEM_OP_MAX_SIZE)
+		return -E2BIG;
+	if (kvm_s390_pv_is_protected(kvm))
+		return -EINVAL;
+	if (mop->flags & KVM_S390_MEMOP_F_SKEY_PROTECTION) {
+		if (access_key_invalid(mop->key))
+			return -EINVAL;
+	} else {
+		mop->key = 0;
+	}
+	if (!(mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY)) {
+		tmpbuf = vmalloc(mop->size);
+		if (!tmpbuf)
+			return -ENOMEM;
+	}
+
+	srcu_idx = srcu_read_lock(&kvm->srcu);
+
+	if (kvm_is_error_gpa(kvm, mop->gaddr)) {
+		r = PGM_ADDRESSING;
+		goto out_unlock;
+	}
+
+	switch (mop->op) {
+	case KVM_S390_MEMOP_ABSOLUTE_READ: {
+		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
+			r = check_gpa_range(kvm, mop->gaddr, mop->size, GACC_FETCH, mop->key);
+		} else {
+			r = access_guest_abs_with_key(kvm, mop->gaddr, tmpbuf,
+						      mop->size, GACC_FETCH, mop->key);
+			if (r == 0) {
+				if (copy_to_user(uaddr, tmpbuf, mop->size))
+					r = -EFAULT;
+			}
+		}
+		break;
+	}
+	case KVM_S390_MEMOP_ABSOLUTE_WRITE: {
+		if (mop->flags & KVM_S390_MEMOP_F_CHECK_ONLY) {
+			r = check_gpa_range(kvm, mop->gaddr, mop->size, GACC_STORE, mop->key);
+		} else {
+			if (copy_from_user(tmpbuf, uaddr, mop->size)) {
+				r = -EFAULT;
+				break;
+			}
+			r = access_guest_abs_with_key(kvm, mop->gaddr, tmpbuf,
+						      mop->size, GACC_STORE, mop->key);
+		}
+		break;
+	}
+	default:
+		r = -EINVAL;
+	}
+
+out_unlock:
+	srcu_read_unlock(&kvm->srcu, srcu_idx);
+
+	vfree(tmpbuf);
+	return r;
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {
@@ -2488,6 +2560,15 @@ long kvm_arch_vm_ioctl(struct file *filp,
 		}
 		break;
 	}
+	case KVM_S390_MEM_OP: {
+		struct kvm_s390_mem_op mem_op;
+
+		if (copy_from_user(&mem_op, argp, sizeof(mem_op)) == 0)
+			r = kvm_s390_vm_mem_op(kvm, &mem_op);
+		else
+			r = -EFAULT;
+		break;
+	}
 	default:
 		r = -ENOTTY;
 	}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 4566f429db2c..4bc7623def87 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -575,6 +575,8 @@ struct kvm_s390_mem_op {
 #define KVM_S390_MEMOP_LOGICAL_WRITE	1
 #define KVM_S390_MEMOP_SIDA_READ	2
 #define KVM_S390_MEMOP_SIDA_WRITE	3
+#define KVM_S390_MEMOP_ABSOLUTE_READ	4
+#define KVM_S390_MEMOP_ABSOLUTE_WRITE	5
 /* flags for kvm_s390_mem_op->flags */
 #define KVM_S390_MEMOP_F_CHECK_ONLY		(1ULL << 0)
 #define KVM_S390_MEMOP_F_INJECT_EXCEPTION	(1ULL << 1)
-- 
2.35.1

[GIT PULL 08/13] KVM: s390: Rename existing vcpu memop functions

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Makes the naming consistent, now that we also have a vm ioctl.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-8-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 36bc73b5f5de..773bccdd446c 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4741,8 +4741,8 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 	return r;
 }
 
-static long kvm_s390_guest_sida_op(struct kvm_vcpu *vcpu,
-				   struct kvm_s390_mem_op *mop)
+static long kvm_s390_vcpu_sida_op(struct kvm_vcpu *vcpu,
+				  struct kvm_s390_mem_op *mop)
 {
 	void __user *uaddr = (void __user *)mop->buf;
 	int r = 0;
@@ -4771,8 +4771,9 @@ static long kvm_s390_guest_sida_op(struct kvm_vcpu *vcpu,
 	}
 	return r;
 }
-static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
-				  struct kvm_s390_mem_op *mop)
+
+static long kvm_s390_vcpu_mem_op(struct kvm_vcpu *vcpu,
+				 struct kvm_s390_mem_op *mop)
 {
 	void __user *uaddr = (void __user *)mop->buf;
 	void *tmpbuf = NULL;
@@ -4835,8 +4836,8 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
 	return r;
 }
 
-static long kvm_s390_guest_memsida_op(struct kvm_vcpu *vcpu,
-				      struct kvm_s390_mem_op *mop)
+static long kvm_s390_vcpu_memsida_op(struct kvm_vcpu *vcpu,
+				     struct kvm_s390_mem_op *mop)
 {
 	int r, srcu_idx;
 
@@ -4845,12 +4846,12 @@ static long kvm_s390_guest_memsida_op(struct kvm_vcpu *vcpu,
 	switch (mop->op) {
 	case KVM_S390_MEMOP_LOGICAL_READ:
 	case KVM_S390_MEMOP_LOGICAL_WRITE:
-		r = kvm_s390_guest_mem_op(vcpu, mop);
+		r = kvm_s390_vcpu_mem_op(vcpu, mop);
 		break;
 	case KVM_S390_MEMOP_SIDA_READ:
 	case KVM_S390_MEMOP_SIDA_WRITE:
 		/* we are locked against sida going away by the vcpu->mutex */
-		r = kvm_s390_guest_sida_op(vcpu, mop);
+		r = kvm_s390_vcpu_sida_op(vcpu, mop);
 		break;
 	default:
 		r = -EINVAL;
@@ -5013,7 +5014,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 		struct kvm_s390_mem_op mem_op;
 
 		if (copy_from_user(&mem_op, argp, sizeof(mem_op)) == 0)
-			r = kvm_s390_guest_memsida_op(vcpu, &mem_op);
+			r = kvm_s390_vcpu_memsida_op(vcpu, &mem_op);
 		else
 			r = -EFAULT;
 		break;
-- 
2.35.1

[GIT PULL 09/13] KVM: s390: Add capability for storage key extension of MEM_OP IOCTL

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Availability of the KVM_CAP_S390_MEM_OP_EXTENSION capability signals that:
* The vcpu MEM_OP IOCTL supports storage key checking.
* The vm MEM_OP IOCTL exists.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-9-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 1 +
 include/uapi/linux/kvm.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 773bccdd446c..c2c26c2aad64 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -564,6 +564,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_S390_VCPU_RESETS:
 	case KVM_CAP_SET_GUEST_DEBUG:
 	case KVM_CAP_S390_DIAG318:
+	case KVM_CAP_S390_MEM_OP_EXTENSION:
 		r = 1;
 		break;
 	case KVM_CAP_SET_GUEST_DEBUG2:
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 4bc7623def87..08756eeea065 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1140,6 +1140,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_VM_GPA_BITS 207
 #define KVM_CAP_XSAVE2 208
 #define KVM_CAP_SYS_ATTRIBUTES 209
+#define KVM_CAP_S390_MEM_OP_EXTENSION 210
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
-- 
2.35.1

[GIT PULL 10/13] KVM: s390: Update api documentation for memop ioctl

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Document all currently existing operations, flags and explain under
which circumstances they are available. Document the recently
introduced absolute operations and the storage key protection flag,
as well as the existing SIDA operations.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20220211182215.2730017-10-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 Documentation/virt/kvm/api.rst | 112 ++++++++++++++++++++++++++-------
 include/uapi/linux/kvm.h       |   2 +-
 2 files changed, 91 insertions(+), 23 deletions(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index a4267104db50..48f23bb80d7f 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -3683,15 +3683,17 @@ The fields in each entry are defined as follows:
 4.89 KVM_S390_MEM_OP
 --------------------
 
-:Capability: KVM_CAP_S390_MEM_OP
+:Capability: KVM_CAP_S390_MEM_OP, KVM_CAP_S390_PROTECTED, KVM_CAP_S390_MEM_OP_EXTENSION
 :Architectures: s390
-:Type: vcpu ioctl
+:Type: vm ioctl, vcpu ioctl
 :Parameters: struct kvm_s390_mem_op (in)
 :Returns: = 0 on success,
           < 0 on generic error (e.g. -EFAULT or -ENOMEM),
           > 0 if an exception occurred while walking the page tables
 
-Read or write data from/to the logical (virtual) memory of a VCPU.
+Read or write data from/to the VM's memory.
+The KVM_CAP_S390_MEM_OP_EXTENSION capability specifies what functionality is
+supported.
 
 Parameters are specified via the following structure::
 
@@ -3701,33 +3703,99 @@ Parameters are specified via the following structure::
 	__u32 size;		/* amount of bytes */
 	__u32 op;		/* type of operation */
 	__u64 buf;		/* buffer in userspace */
-	__u8 ar;		/* the access register number */
-	__u8 reserved[31];	/* should be set to 0 */
+	union {
+		struct {
+			__u8 ar;	/* the access register number */
+			__u8 key;	/* access key, ignored if flag unset */
+		};
+		__u32 sida_offset; /* offset into the sida */
+		__u8 reserved[32]; /* ignored */
+	};
   };
 
-The type of operation is specified in the "op" field. It is either
-KVM_S390_MEMOP_LOGICAL_READ for reading from logical memory space or
-KVM_S390_MEMOP_LOGICAL_WRITE for writing to logical memory space. The
-KVM_S390_MEMOP_F_CHECK_ONLY flag can be set in the "flags" field to check
-whether the corresponding memory access would create an access exception
-(without touching the data in the memory at the destination). In case an
-access exception occurred while walking the MMU tables of the guest, the
-ioctl returns a positive error number to indicate the type of exception.
-This exception is also raised directly at the corresponding VCPU if the
-flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field.
-
 The start address of the memory region has to be specified in the "gaddr"
 field, and the length of the region in the "size" field (which must not
 be 0). The maximum value for "size" can be obtained by checking the
 KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the
 userspace application where the read data should be written to for
-KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is
-stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY
-is specified, "buf" is unused and can be NULL. "ar" designates the access
-register number to be used; the valid range is 0..15.
+a read access, or where the data that should be written is stored for
+a write access.  The "reserved" field is meant for future extensions.
+Reserved and unused values are ignored. Future extension that add members must
+introduce new flags.
 
-The "reserved" field is meant for future extensions. It is not used by
-KVM with the currently defined set of flags.
+The type of operation is specified in the "op" field. Flags modifying
+their behavior can be set in the "flags" field. Undefined flag bits must
+be set to 0.
+
+Possible operations are:
+  * ``KVM_S390_MEMOP_LOGICAL_READ``
+  * ``KVM_S390_MEMOP_LOGICAL_WRITE``
+  * ``KVM_S390_MEMOP_ABSOLUTE_READ``
+  * ``KVM_S390_MEMOP_ABSOLUTE_WRITE``
+  * ``KVM_S390_MEMOP_SIDA_READ``
+  * ``KVM_S390_MEMOP_SIDA_WRITE``
+
+Logical read/write:
+^^^^^^^^^^^^^^^^^^^
+
+Access logical memory, i.e. translate the given guest address to an absolute
+address given the state of the VCPU and use the absolute address as target of
+the access. "ar" designates the access register number to be used; the valid
+range is 0..15.
+Logical accesses are permitted for the VCPU ioctl only.
+Logical accesses are permitted for non-protected guests only.
+
+Supported flags:
+  * ``KVM_S390_MEMOP_F_CHECK_ONLY``
+  * ``KVM_S390_MEMOP_F_INJECT_EXCEPTION``
+  * ``KVM_S390_MEMOP_F_SKEY_PROTECTION``
+
+The KVM_S390_MEMOP_F_CHECK_ONLY flag can be set to check whether the
+corresponding memory access would cause an access exception; however,
+no actual access to the data in memory at the destination is performed.
+In this case, "buf" is unused and can be NULL.
+
+In case an access exception occurred during the access (or would occur
+in case of KVM_S390_MEMOP_F_CHECK_ONLY), the ioctl returns a positive
+error number indicating the type of exception. This exception is also
+raised directly at the corresponding VCPU if the flag
+KVM_S390_MEMOP_F_INJECT_EXCEPTION is set.
+
+If the KVM_S390_MEMOP_F_SKEY_PROTECTION flag is set, storage key
+protection is also in effect and may cause exceptions if accesses are
+prohibited given the access key passed in "key".
+KVM_S390_MEMOP_F_SKEY_PROTECTION is available if KVM_CAP_S390_MEM_OP_EXTENSION
+is > 0.
+
+Absolute read/write:
+^^^^^^^^^^^^^^^^^^^^
+
+Access absolute memory. This operation is intended to be used with the
+KVM_S390_MEMOP_F_SKEY_PROTECTION flag, to allow accessing memory and performing
+the checks required for storage key protection as one operation (as opposed to
+user space getting the storage keys, performing the checks, and accessing
+memory thereafter, which could lead to a delay between check and access).
+Absolute accesses are permitted for the VM ioctl if KVM_CAP_S390_MEM_OP_EXTENSION
+is > 0.
+Currently absolute accesses are not permitted for VCPU ioctls.
+Absolute accesses are permitted for non-protected guests only.
+
+Supported flags:
+  * ``KVM_S390_MEMOP_F_CHECK_ONLY``
+  * ``KVM_S390_MEMOP_F_SKEY_PROTECTION``
+
+The semantics of the flags are as for logical accesses.
+
+SIDA read/write:
+^^^^^^^^^^^^^^^^
+
+Access the secure instruction data area which contains memory operands necessary
+for instruction emulation for protected guests.
+SIDA accesses are available if the KVM_CAP_S390_PROTECTED capability is available.
+SIDA accesses are permitted for the VCPU ioctl only.
+SIDA accesses are permitted for protected guests only.
+
+No flags are supported.
 
 4.90 KVM_S390_GET_SKEYS
 -----------------------
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 08756eeea065..dbc550bbd9fa 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -567,7 +567,7 @@ struct kvm_s390_mem_op {
 			__u8 key;	/* access key, ignored if flag unset */
 		};
 		__u32 sida_offset; /* offset into the sida */
-		__u8 reserved[32]; /* should be set to 0 */
+		__u8 reserved[32]; /* ignored */
 	};
 };
 /* types for kvm_s390_mem_op->op */
-- 
2.35.1

[GIT PULL 11/13] selftests: kvm: Check whether SIDA memop fails for normal guests

[Christian Borntraeger]

From: Thomas Huth <thuth@redhat.com>

Commit 2c212e1baedc ("KVM: s390: Return error on SIDA memop on normal
guest") fixed the behavior of the SIDA memops for normal guests. It
would be nice to have a way to test whether the current kernel has
the fix applied or not. Thus add a check to the KVM selftests for
these two memops.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220215074824.188440-1-thuth@redhat.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 tools/testing/selftests/kvm/s390x/memop.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tools/testing/selftests/kvm/s390x/memop.c b/tools/testing/selftests/kvm/s390x/memop.c
index 9f49ead380ab..d19c3ffdea3f 100644
--- a/tools/testing/selftests/kvm/s390x/memop.c
+++ b/tools/testing/selftests/kvm/s390x/memop.c
@@ -160,6 +160,21 @@ int main(int argc, char *argv[])
 	run->psw_mask &= ~(3UL << (63 - 17));   /* Disable AR mode */
 	vcpu_run(vm, VCPU_ID);                  /* Run to sync new state */
 
+	/* Check that the SIDA calls are rejected for non-protected guests */
+	ksmo.gaddr = 0;
+	ksmo.flags = 0;
+	ksmo.size = 8;
+	ksmo.op = KVM_S390_MEMOP_SIDA_READ;
+	ksmo.buf = (uintptr_t)mem1;
+	ksmo.sida_offset = 0x1c0;
+	rv = _vcpu_ioctl(vm, VCPU_ID, KVM_S390_MEM_OP, &ksmo);
+	TEST_ASSERT(rv == -1 && errno == EINVAL,
+		    "ioctl does not reject SIDA_READ in non-protected mode");
+	ksmo.op = KVM_S390_MEMOP_SIDA_WRITE;
+	rv = _vcpu_ioctl(vm, VCPU_ID, KVM_S390_MEM_OP, &ksmo);
+	TEST_ASSERT(rv == -1 && errno == EINVAL,
+		    "ioctl does not reject SIDA_WRITE in non-protected mode");
+
 	kvm_vm_free(vm);
 
 	return 0;
-- 
2.35.1

[GIT PULL 12/13] KVM: s390: Clarify key argument for MEM_OP in api docs

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Clarify that the key argument represents the access key, not the whole
storage key.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Link: https://lore.kernel.org/r/20220221143657.3712481-1-scgl@linux.ibm.com
Fixes: 5e35d0eb472b ("KVM: s390: Update api documentation for memop ioctl")
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 Documentation/virt/kvm/api.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 48f23bb80d7f..622667cc87ef 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -3763,7 +3763,7 @@ KVM_S390_MEMOP_F_INJECT_EXCEPTION is set.
 
 If the KVM_S390_MEMOP_F_SKEY_PROTECTION flag is set, storage key
 protection is also in effect and may cause exceptions if accesses are
-prohibited given the access key passed in "key".
+prohibited given the access key designated by "key"; the valid range is 0..15.
 KVM_S390_MEMOP_F_SKEY_PROTECTION is available if KVM_CAP_S390_MEM_OP_EXTENSION
 is > 0.
 
-- 
2.35.1

[GIT PULL 13/13] KVM: s390: Add missing vm MEM_OP size check

[Christian Borntraeger]

From: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

Check that size is not zero, preventing the following warning:

WARNING: CPU: 0 PID: 9692 at mm/vmalloc.c:3059 __vmalloc_node_range+0x528/0x648
Modules linked in:
CPU: 0 PID: 9692 Comm: memop Not tainted 5.17.0-rc3-e4+ #80
Hardware name: IBM 8561 T01 701 (LPAR)
Krnl PSW : 0704c00180000000 0000000082dc584c (__vmalloc_node_range+0x52c/0x648)
           R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000083 ffffffffffffffff 0000000000000000 0000000000000001
           0000038000000000 000003ff80000000 0000000000000cc0 000000008ebb8000
           0000000087a8a700 000000004040aeb1 000003ffd9f7dec8 000000008ebb8000
           000000009d9b8000 000000000102a1b4 00000380035afb68 00000380035afaa8
Krnl Code: 0000000082dc583e: d028a7f4ff80        trtr    2036(41,%r10),3968(%r15)
           0000000082dc5844: af000000            mc      0,0
          #0000000082dc5848: af000000            mc      0,0
          >0000000082dc584c: a7d90000            lghi    %r13,0
           0000000082dc5850: b904002d            lgr     %r2,%r13
           0000000082dc5854: eb6ff1080004        lmg     %r6,%r15,264(%r15)
           0000000082dc585a: 07fe                bcr     15,%r14
           0000000082dc585c: 47000700            bc      0,1792
Call Trace:
 [<0000000082dc584c>] __vmalloc_node_range+0x52c/0x648
 [<0000000082dc5b62>] vmalloc+0x5a/0x68
 [<000003ff8067f4ca>] kvm_arch_vm_ioctl+0x2da/0x2a30 [kvm]
 [<000003ff806705bc>] kvm_vm_ioctl+0x4ec/0x978 [kvm]
 [<0000000082e562fe>] __s390x_sys_ioctl+0xbe/0x100
 [<000000008360a9bc>] __do_syscall+0x1d4/0x200
 [<0000000083618bd2>] system_call+0x82/0xb0
Last Breaking-Event-Address:
 [<0000000082dc5348>] __vmalloc_node_range+0x28/0x648

Other than the warning, there is no ill effect from the missing check,
the condition is detected by subsequent code and causes a return
with ENOMEM.

Fixes: ef11c9463ae0 (KVM: s390: Add vm IOCTL for key checked guest absolute memory access)
Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Link: https://lore.kernel.org/r/20220221163237.4122868-1-scgl@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index c2c26c2aad64..e056ad86ccd2 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2374,7 +2374,7 @@ static int kvm_s390_vm_mem_op(struct kvm *kvm, struct kvm_s390_mem_op *mop)
 
 	supported_flags = KVM_S390_MEMOP_F_SKEY_PROTECTION
 			  | KVM_S390_MEMOP_F_CHECK_ONLY;
-	if (mop->flags & ~supported_flags)
+	if (mop->flags & ~supported_flags || !mop->size)
 		return -EINVAL;
 	if (mop->size > MEM_OP_MAX_SIZE)
 		return -E2BIG;
-- 
2.35.1

Re: [GIT PULL 00/13] KVM: s390: Changes for 5.18 part1

[Christian Borntraeger]

Am 22.02.22 um 10:48 schrieb Christian Borntraeger:
> ----------------------------------------------------------------
> Christian Borntraeger (1):
>        KVM: s390: MAINTAINERS: promote Claudio Imbrenda
> 
> Janis Schoetterl-Glausch (11):
>        s390/uaccess: Add copy_from/to_user_key functions

Forgot to mention this: this contains one s390 patch that is acked by the s390 maintainer.

Re: [GIT PULL 00/13] KVM: s390: Changes for 5.18 part1

[Paolo Bonzini]

On 2/22/22 10:48, Christian Borntraeger wrote:
> Paolo,
> 
> first part of the s390 parts of KVM for 5.18. This is on top of the fix
> that went into Linus tree, so it will move kvm/next to something between
> rc3 and rc4.
> 
> I added 2 later fixups for the storage key patches on top. Let me know if
> you prefer them folded in.
> 
> We might do a 2nd pull request later on depending on timing, review and
> other constraints
> with
> - rewritten selftest for memop
> - ultravisor device (could also go via s390 tree)
> - parts/all of Claudios lazy destroy
> - parts/all of PCI passthru (could be later and might go via s390 tree as
>    well via a topic branch)
> - followup to guest entry/exit work if we find a small solution
> - adapter interruption virtualization facility for secure guests
> 
> The following changes since commit 09a93c1df3eafa43bcdfd7bf837c574911f12f55:
> 
>    Merge tag 'kvm-s390-kernel-access' from emailed bundle (2022-02-09 09:14:22 -0800)
> 
> are available in the Git repository at:
> 
>    git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git  tags/kvm-s390-next-5.18-1
> 
> for you to fetch changes up to 3d9042f8b923810c169ece02d91c70ec498eff0b:
> 
>    KVM: s390: Add missing vm MEM_OP size check (2022-02-22 09:16:18 +0100)

Pulled, thanks.

Paolo