[GIT,PULL,1/8] KVM: s390: Fix SORTL and DFLTCC instruction format error in __insn32_query

Commit Message

Janosch Frank Sept. 16, 2024, 10:42 a.m. UTC

From: Hariharan Mari <[e-mail]>

The __insn32_query() function incorrectly uses the RRF instruction format
for both the SORTL (RRE format) and DFLTCC (RRF format) instructions.
To fix this issue, add separate query functions for SORTL and DFLTCC that
use the appropriate instruction formats.

Additionally pass the query operand as a pointer to the entire array
of 32 elements to slightly optimize performance and readability.

Fixes: d668139718a9 ("KVM: s390: provide query function for instructions returning 32 byte")
Suggested-by: Heiko Carstens <[e-mail]>
Reviewed-by: Juergen Christ <[e-mail]>
Signed-off-by: Hariharan Mari <[e-mail]>
Signed-off-by: Janosch Frank <[e-mail]>
---
 arch/s390/kvm/kvm-s390.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

Patch

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 0fd96860fc45..bb7134faaebf 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -348,20 +348,29 @@  static inline int plo_test_bit(unsigned char nr)
 	return cc == 0;
 }
 
-static __always_inline void __insn32_query(unsigned int opcode, u8 *query)
+static __always_inline void __sortl_query(u8 (*query)[32])
 {
 	asm volatile(
 		"	lghi	0,0\n"
-		"	lgr	1,%[query]\n"
+		"	la	1,%[query]\n"
 		/* Parameter registers are ignored */
-		"	.insn	rrf,%[opc] << 16,2,4,6,0\n"
+		"	.insn	rre,0xb9380000,2,4\n"
+		: [query] "=R" (*query)
 		:
-		: [query] "d" ((unsigned long)query), [opc] "i" (opcode)
-		: "cc", "memory", "0", "1");
+		: "cc", "0", "1");
 }
 
-#define INSN_SORTL 0xb938
-#define INSN_DFLTCC 0xb939
+static __always_inline void __dfltcc_query(u8 (*query)[32])
+{
+	asm volatile(
+		"	lghi	0,0\n"
+		"	la	1,%[query]\n"
+		/* Parameter registers are ignored */
+		"	.insn	rrf,0xb9390000,2,4,6,0\n"
+		: [query] "=R" (*query)
+		:
+		: "cc", "0", "1");
+}
 
 static void __init kvm_s390_cpu_feat_init(void)
 {
@@ -415,10 +424,10 @@  static void __init kvm_s390_cpu_feat_init(void)
 			      kvm_s390_available_subfunc.kdsa);
 
 	if (test_facility(150)) /* SORTL */
-		__insn32_query(INSN_SORTL, kvm_s390_available_subfunc.sortl);
+		__sortl_query(&kvm_s390_available_subfunc.sortl);
 
 	if (test_facility(151)) /* DFLTCC */
-		__insn32_query(INSN_DFLTCC, kvm_s390_available_subfunc.dfltcc);
+		__dfltcc_query(&kvm_s390_available_subfunc.dfltcc);
 
 	if (MACHINE_HAS_ESOP)
 		allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP);