Commit 08288241 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

Merge tag 'kvm-s390-next-5.18-1' of... 

Merge tag 'kvm-s390-next-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Changes for 5.18 part1

- add Claudio as Maintainer
- first step to do proper storage key checking
- testcase for missing memop check
parents 1bbc60d0 3d9042f8

Documentation/virt/kvm/api.rst

+90 −22
Original line number Diff line number Diff line
@@ -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 */

	union {

		struct {

			__u8 ar;	/* the access register number */

	__u8 reserved[31];	/* should be set to 0 */

			__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 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 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.



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.



The "reserved" field is meant for future extensions. It is not used by

KVM with the currently defined set of flags.

No flags are supported.



4.90 KVM_S390_GET_SKEYS

-----------------------

MAINTAINERS

+2 −2
Original line number Diff line number Diff line
@@ -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/
@@ -13571,7 +13571,7 @@ F: tools/testing/selftests/nci/ 








NFS, SUNRPC, AND LOCKD CLIENTS









M:	Trond Myklebust <trond.myklebust@hammerspace.com>









M:	Anna Schumaker <anna.schumaker@netapp.com>









M:	Anna Schumaker <anna@kernel.org>









L:	linux-nfs@vger.kernel.org









S:	Maintained









W:	http://client.linux-nfs.org
































arch/s390/include/asm/ctl_reg.h



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@@ -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)
































arch/s390/include/asm/page.h



+2
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@@ -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
































arch/s390/include/asm/uaccess.h



+22
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@@ -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));