Commit 6b33e68a authored by Nico Boehr's avatar Nico Boehr Committed by Janosch Frank
Browse files

s390/entry: sort out physical vs virtual pointers usage in sie64a 



Fix virtual vs physical address confusion (which currently are the
same).

sie_block is accessed in entry.S and passed it to hardware, which is why
both its physical and virtual address are needed. To avoid every caller
having to do the virtual-physical conversion, add a new function sie64a()
which converts the virtual address to physical.

Signed-off-by: default avatarNico Boehr <nrb@linux.ibm.com>
Reviewed-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20221020143159.294605-3-nrb@linux.ibm.com


Message-Id: <20221020143159.294605-3-nrb@linux.ibm.com>
Signed-off-by: default avatarJanosch Frank <frankja@linux.ibm.com>
parent 079f0c21

arch/s390/include/asm/kvm_host.h

+7 −1
Original line number Diff line number Diff line
@@ -1017,7 +1017,13 @@ void kvm_arch_crypto_clear_masks(struct kvm *kvm); 
void kvm_arch_crypto_set_masks(struct kvm *kvm, unsigned long *apm,

			       unsigned long *aqm, unsigned long *adm);



extern int sie64a(struct kvm_s390_sie_block *, u64 *);

int __sie64a(phys_addr_t sie_block_phys, struct kvm_s390_sie_block *sie_block, u64 *rsa);



static inline int sie64a(struct kvm_s390_sie_block *sie_block, u64 *rsa)

{

	return __sie64a(virt_to_phys(sie_block), sie_block, rsa);

}



extern char sie_exit;



extern int kvm_s390_gisc_register(struct kvm *kvm, u32 gisc);

arch/s390/include/asm/stacktrace.h

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ struct stack_frame { 
			unsigned long sie_savearea;

			unsigned long sie_reason;

			unsigned long sie_flags;

			unsigned long sie_control_block_phys;

		};

	};

	unsigned long gprs[10];

arch/s390/kernel/asm-offsets.c

+1 −0
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ int main(void) 
	OFFSET(__SF_SIE_SAVEAREA, stack_frame, sie_savearea);

	OFFSET(__SF_SIE_REASON, stack_frame, sie_reason);

	OFFSET(__SF_SIE_FLAGS, stack_frame, sie_flags);

	OFFSET(__SF_SIE_CONTROL_PHYS, stack_frame, sie_control_block_phys);

	DEFINE(STACK_FRAME_OVERHEAD, sizeof(struct stack_frame));

	BLANK();

	/* idle data offsets */

arch/s390/kernel/entry.S

+15 −11
Original line number Diff line number Diff line
@@ -225,18 +225,20 @@ ENDPROC(__switch_to) 


#if IS_ENABLED(CONFIG_KVM)

/*

 * sie64a calling convention:

 * %r2 pointer to sie control block

 * %r3 guest register save area

 * __sie64a calling convention:

 * %r2 pointer to sie control block phys

 * %r3 pointer to sie control block virt

 * %r4 guest register save area

 */

ENTRY(sie64a)

ENTRY(__sie64a)

	stmg	%r6,%r14,__SF_GPRS(%r15)	# save kernel registers

	lg	%r12,__LC_CURRENT

	stg	%r2,__SF_SIE_CONTROL(%r15)	# save control block pointer

	stg	%r3,__SF_SIE_SAVEAREA(%r15)	# save guest register save area

	stg	%r2,__SF_SIE_CONTROL_PHYS(%r15)	# save sie block physical..

	stg	%r3,__SF_SIE_CONTROL(%r15)	# ...and virtual addresses

	stg	%r4,__SF_SIE_SAVEAREA(%r15)	# save guest register save area

	xc	__SF_SIE_REASON(8,%r15),__SF_SIE_REASON(%r15) # reason code = 0

	mvc	__SF_SIE_FLAGS(8,%r15),__TI_flags(%r12) # copy thread flags

	lmg	%r0,%r13,0(%r3)			# load guest gprs 0-13

	lmg	%r0,%r13,0(%r4)			# load guest gprs 0-13

	lg	%r14,__LC_GMAP			# get gmap pointer

	ltgr	%r14,%r14

	jz	.Lsie_gmap
@@ -248,6 +250,7 @@ ENTRY(sie64a) 
	jnz	.Lsie_skip

	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU

	jo	.Lsie_skip			# exit if fp/vx regs changed

	lg	%r14,__SF_SIE_CONTROL_PHYS(%r15)	# get sie block phys addr

	BPEXIT	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)

.Lsie_entry:

	sie	0(%r14)
@@ -258,13 +261,14 @@ ENTRY(sie64a) 
	BPOFF

	BPENTER	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)

.Lsie_skip:

	lg	%r14,__SF_SIE_CONTROL(%r15)	# get control block pointer

	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE

	lctlg	%c1,%c1,__LC_KERNEL_ASCE	# load primary asce

.Lsie_done:

# some program checks are suppressing. C code (e.g. do_protection_exception)

# will rewind the PSW by the ILC, which is often 4 bytes in case of SIE. There

# are some corner cases (e.g. runtime instrumentation) where ILC is unpredictable.

# Other instructions between sie64a and .Lsie_done should not cause program

# Other instructions between __sie64a and .Lsie_done should not cause program

# interrupts. So lets use 3 nops as a landing pad for all possible rewinds.

.Lrewind_pad6:

	nopr	7
@@ -293,8 +297,8 @@ sie_exit: 
	EX_TABLE(.Lrewind_pad4,.Lsie_fault)

	EX_TABLE(.Lrewind_pad2,.Lsie_fault)

	EX_TABLE(sie_exit,.Lsie_fault)

ENDPROC(sie64a)

EXPORT_SYMBOL(sie64a)

ENDPROC(__sie64a)

EXPORT_SYMBOL(__sie64a)

EXPORT_SYMBOL(sie_exit)

#endif
@@ -373,7 +377,7 @@ ENTRY(pgm_check_handler) 
	j	3f			# -> fault in user space

.Lpgm_skip_asce:

#if IS_ENABLED(CONFIG_KVM)

	# cleanup critical section for program checks in sie64a

	# cleanup critical section for program checks in __sie64a

	OUTSIDE	%r9,.Lsie_gmap,.Lsie_done,1f

	SIEEXIT

	lghi	%r10,_PIF_GUEST_FAULT