[PATCH v3 13/23] KVM: s390: arm64: Query Available Arm features

[Steffen Eiden <seiden@linux.ibm.com>]

QAAF enables s390 hosts to gain information about the support
and handling of various arm features supported by the machine.

Function code 1 provides general information about available formats,
machine defined content of system/id register, and other various
information for running arm guests.

Function code 2 provides a initialised save area.

Co-developed-by: Andreas Grapentin <gra@linux.ibm.com>
Signed-off-by: Andreas Grapentin <gra@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
 arch/s390/include/asm/aef.h                  |  12 +++
 arch/s390/include/asm/kvm_host_arm64_types.h | 115 +++++++++++++++++++++++++++
 arch/s390/include/asm/sae.h                  |  26 ++++++
 arch/s390/kernel/Makefile                    |   2 +-
 arch/s390/kernel/aef.c                       |  94 ++++++++++++++++++++++
 arch/s390/kvm/arm64/Makefile                 |   1 +
 arch/s390/kvm/arm64/arm.c                    |   6 +-
 arch/s390/kvm/arm64/qaaf.c                   |  83 +++++++++++++++++++
 arch/s390/kvm/arm64/qaaf.h                   |  12 +++
 arch/s390/tools/opcodes.txt                  |   1 +
 10 files changed, 350 insertions(+), 2 deletions(-)

diff --git a/arch/s390/include/asm/aef.h b/arch/s390/include/asm/aef.h
new file mode 100644
index 000000000000..06519cc575be
--- /dev/null
+++ b/arch/s390/include/asm/aef.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_S390_AEF_H
+#define _ASM_S390_AEF_H
+
+#include <asm/kvm_host_arm64_types.h>
+
+const struct kvm_sae_save_area *aef_gisrsa(void);
+const struct qaaf_qmc_block *aef_qmc(void);
+bool aef_usable(void);
+
+#endif /* _ASM_S390_AEF_H */
diff --git a/arch/s390/include/asm/kvm_host_arm64_types.h b/arch/s390/include/asm/kvm_host_arm64_types.h
index 8783a66d3029..d9471f3b0d46 100644
--- a/arch/s390/include/asm/kvm_host_arm64_types.h
+++ b/arch/s390/include/asm/kvm_host_arm64_types.h
@@ -121,4 +121,119 @@ struct kvm_sae_save_area {
 } __packed __aligned(PAGE_SIZE);
 static_assert(sizeof(struct kvm_sae_save_area) == PAGE_SIZE);
 
+#define QAAF_FC_QMC	1
+#define QAAF_FC_GISRSA	2
+
+union qaaf_gr0_gisrsa {
+	struct {
+		u8 _0000[6];
+		u8 saf;
+		u8 : 2;
+		u8 fc : 6;
+	};
+	u64 val;
+};
+
+static_assert(sizeof(union qaaf_gr0_gisrsa) == sizeof(u64));
+
+/* QAAF Query Model Capabilities */
+struct qaaf_qmc_block {
+	u64	_0000;			/* 0x0000 */
+	u8	ssdf;			/* 0x0008 */
+	u8	_0009;			/* 0x0009 */
+	u8	ssaf;			/* 0x000a */
+	u8	_000b[3];		/* 0x000b */
+	u16	maxncpu;		/* 0x000e */
+	u64	_0010[2];		/* 0x0010 */
+	u64	regs[0x1fc];		/* 0x0020 */
+} __aligned(PAGE_SIZE);
+static_assert(sizeof(struct qaaf_qmc_block) == PAGE_SIZE);
+
+union qaaf_block {
+	struct qaaf_qmc_block qmc;
+	struct kvm_sae_save_area save_area;
+} __aligned(PAGE_SIZE);
+static_assert(sizeof(union qaaf_block) == PAGE_SIZE);
+
+/*
+ * Keep in sync with mapping from SYS_* to QAAF_* in qaaf.c!
+ */
+enum {
+	QAAF_REG_MIDR_EL1		= 0x00,
+	/* 0x01-0x04 reserved */
+	QAAF_REG_MPIDR_EL1		= 0x05,
+	QAAF_REG_REVIDR_EL1		= 0x06,
+	/* 0x07 reserved */
+	QAAF_REG_ID_PFR0_EL1		= 0x08,
+	QAAF_REG_ID_PFR1_EL1		= 0x09,
+	QAAF_REG_ID_DFR0_EL1		= 0x0a,
+	QAAF_REG_ID_AFR0_EL1		= 0x0b,
+	QAAF_REG_ID_MMFR0_EL1		= 0x0c,
+	QAAF_REG_ID_MMFR1_EL1		= 0x0d,
+	QAAF_REG_ID_MMFR2_EL1		= 0x0e,
+	QAAF_REG_ID_MMFR3_EL1		= 0x0f,
+	QAAF_REG_ID_ISAR0_EL1		= 0x10,
+	QAAF_REG_ID_ISAR1_EL1		= 0x11,
+	QAAF_REG_ID_ISAR2_EL1		= 0x12,
+	QAAF_REG_ID_ISAR3_EL1		= 0x13,
+	QAAF_REG_ID_ISAR4_EL1		= 0x14,
+	QAAF_REG_ID_ISAR5_EL1		= 0x15,
+	QAAF_REG_ID_MMFR4_EL1		= 0x16,
+	QAAF_REG_ID_ISAR6_EL1		= 0x17,
+	QAAF_REG_MVFR0_EL1		= 0x18,
+	QAAF_REG_MVFR1_EL1		= 0x19,
+	QAAF_REG_MVFR2_EL1		= 0x1a,
+	/* 0x1b reserved */
+	QAAF_REG_ID_PFR2_EL1		= 0x1c,
+	QAAF_REG_ID_DFR1_EL1		= 0x1d,
+	QAAF_REG_ID_MMFR5_EL1		= 0x1e,
+	/* 0x1f reserved */
+	QAAF_REG_ID_AA64PFR0_EL1	= 0x20,
+	QAAF_REG_ID_AA64PFR1_EL1	= 0x21,
+	QAAF_REG_ID_AA64PFR2_EL1	= 0x22,
+	/* 0x23 reserved */
+	QAAF_REG_ID_AA64ZFR0_EL1	= 0x24,
+	QAAF_REG_ID_AA64SMFR0_EL1	= 0x25,
+	/* 0x26 reserved */
+	QAAF_REG_ID_AA64FPFR0_EL1	= 0x27,
+	QAAF_REG_ID_AA64DFR0_EL1	= 0x28,
+	QAAF_REG_ID_AA64DFR1_EL1	= 0x29,
+	QAAF_REG_ID_AA64DFR2_EL1	= 0x2a,
+	/* 0x2b reserved */
+	QAAF_REG_ID_AA64AFR0_EL1	= 0x2c,
+	QAAF_REG_ID_AA64AFR1_EL1	= 0x2d,
+	/* 0x2e,0x2f reserved */
+	QAAF_REG_ID_AA64ISAR0_EL1	= 0x30,
+	QAAF_REG_ID_AA64ISAR1_EL1	= 0x31,
+	QAAF_REG_ID_AA64ISAR2_EL1	= 0x32,
+	QAAF_REG_ID_AA64ISAR3_EL1	= 0x33,
+	/* 0x34-0x37 reserved */
+	QAAF_REG_ID_AA64MMFR0_EL1	= 0x38,
+	QAAF_REG_ID_AA64MMFR1_EL1	= 0x39,
+	QAAF_REG_ID_AA64MMFR2_EL1	= 0x3a,
+	QAAF_REG_ID_AA64MMFR3_EL1	= 0x3b,
+	QAAF_REG_ID_AA64MMFR4_EL1	= 0x3c,
+	/* 0x3d-0x3f reserved */
+	QAAF_REG_CNTFRQ_EL0		= 0x40,
+	QAAF_REG_CTR_EL0		= 0x41,
+	QAAF_REG_AIDR_EL1		= 0x42,
+	/* 0x43-0x47 reserved */
+	QAAF_IRPTC			= 0x48,
+	/* 0x49 reserved */
+	QAAF_REG_ICH_VTR_EL2		= 0x4a,
+	QAAF_GIC_ATTR			= 0x4b,
+	/* 0x4c-0x4f reserved */
+	QAAF_REG_PMMIR_EL1		= 0x50,
+	QAAF_REG_PMCR_EL0		= 0x51,
+	QAAF_REG_PMCEID0_EL0		= 0x52,
+	QAAF_REG_PMCEID1_EL0		= 0x53,
+	/* 0x54-0x1fb reserved */
+	_QAAF_MAX
+};
+
+static_assert((sizeof(struct qaaf_qmc_block) -
+	       offsetof(struct qaaf_qmc_block, regs)) /
+		      8 >=
+	      _QAAF_MAX);
+
 #endif /* ASM_KVM_HOST_ARM64_TYPES_H */
diff --git a/arch/s390/include/asm/sae.h b/arch/s390/include/asm/sae.h
index cac4fbf58e88..d1b9af770108 100644
--- a/arch/s390/include/asm/sae.h
+++ b/arch/s390/include/asm/sae.h
@@ -12,6 +12,7 @@
 asmlinkage void sae(phys_addr_t sae_block_phys);
 
 #include <linux/io.h>
+#include <asm/extable.h>
 #include <asm/kvm_host_arm64_types.h>
 #include <asm/insn-common-asm-emit.h>
 
@@ -112,5 +113,30 @@ static __always_inline void lasrm(struct kvm_sae_save_area *save_area)
 	);
 }
 
+/**
+ * qaaf() - Query Available Arm Features
+ * @gr0: QAAF function code
+ * @qaaf_block: Pointer to the page for the output
+ *
+ * Perform QAAF. The result is written to qaaf_block.
+ */
+static __always_inline int qaaf(u64 gr0, union qaaf_block *qaaf_block)
+{
+	int exception = 1;
+
+	asm_inline volatile(
+		"	lgr	0,%[r0]\n"
+		"0:	.insn	rre,0xb9ad0000,%[r1],0\n"
+		"	lhi	%[exc],0\n"
+		"1:\n"
+		EX_TABLE_INSN(0b, 1b)
+		: "=m" (*qaaf_block), [exc] "+d" (exception)
+		: [r1] "a" (qaaf_block), [r0] "d" (gr0)
+		: "0"
+	);
+
+	return exception;
+}
+
 #endif /* !__ASSEMBLER__ */
 #endif /* __ASM_S390_SAE_H */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index f84b8fb41331..0f3b9fcd1885 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -46,7 +46,7 @@ obj-y	+= runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
 obj-y	+= entry.o reipl.o kdebugfs.o alternative.o skey.o
 obj-y	+= nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o
 obj-y	+= smp.o text_amode31.o stacktrace.o abs_lowcore.o facility.o uv.o wti.o
-obj-y	+= diag/
+obj-y	+= diag/ aef.o
 
 always-$(KBUILD_BUILTIN)	+= vmlinux.lds
 
diff --git a/arch/s390/kernel/aef.c b/arch/s390/kernel/aef.c
new file mode 100644
index 000000000000..31e18953d7b3
--- /dev/null
+++ b/arch/s390/kernel/aef.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/export.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/slab.h>
+
+#include <asm/aef.h>
+#include <asm/sae.h>
+#include <asm/sclp.h>
+
+static struct qaaf_qmc_block qmc = {};
+static struct kvm_sae_save_area save_area = {};
+
+const struct kvm_sae_save_area *aef_gisrsa(void)
+{
+	return &save_area;
+}
+EXPORT_SYMBOL_GPL(aef_gisrsa);
+
+const struct qaaf_qmc_block *aef_qmc(void)
+{
+	return &qmc;
+}
+EXPORT_SYMBOL_GPL(aef_qmc);
+
+/* set once the QMC block and GISRSA save area were fetched successfully */
+static bool aef_valid;
+
+/**
+ * aef_usable() - Report whether the QAAF query data is available
+ *
+ * false if sclp.has_aef is not set or the QAAF instruction failed.
+ */
+bool aef_usable(void)
+{
+	return aef_valid;
+}
+EXPORT_SYMBOL_GPL(aef_usable);
+
+static int __init aef_init_save_area(void)
+{
+	int ret;
+
+	union qaaf_gr0_gisrsa gr0 = {
+		.fc = QAAF_FC_GISRSA,
+		.saf = SAE_SAVE_AREA_FORMAT_0,
+	};
+
+	if (!sclp.has_aef)
+		return 0;
+
+	ret = qaaf(gr0.val, (union qaaf_block *)&save_area);
+	if (ret)
+		return -EIO;
+
+	return 0;
+}
+
+static int __init aef_query_info(void)
+{
+	int ret;
+
+	if (!sclp.has_aef)
+		return 0;
+
+	ret = qaaf(QAAF_FC_QMC, (union qaaf_block *)&qmc);
+	if (ret)
+		return -EIO;
+
+	return 0;
+}
+
+static int __init aef_sysfs_init(void)
+{
+	int rc;
+
+	if (!sclp.has_aef)
+		return 0;
+
+	rc = aef_query_info();
+	if (rc)
+		return rc;
+
+	rc = aef_init_save_area();
+	if (rc)
+		return rc;
+
+	aef_valid = true;
+
+	return 0;
+}
+
+arch_initcall(aef_sysfs_init);
diff --git a/arch/s390/kvm/arm64/Makefile b/arch/s390/kvm/arm64/Makefile
index b48dc65b7aaa..e9587c6d6de9 100644
--- a/arch/s390/kvm/arm64/Makefile
+++ b/arch/s390/kvm/arm64/Makefile
@@ -16,6 +16,7 @@ kvm-arm64-local := \
 	inject_fault.o \
 	mmio.o \
 	mmu.o \
+	qaaf.o \
 	reset.o
 
 kvm-arm64-obj := $(kvm-arm64-local)
diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
index 29d3add0bbda..62c2b45599b9 100644
--- a/arch/s390/kvm/arm64/arm.c
+++ b/arch/s390/kvm/arm64/arm.c
@@ -11,6 +11,7 @@
 #include <linux/bitfield.h>
 
 #include <asm/access-regs.h>
+#include <asm/aef.h>
 
 #include <arm64/kvm_emulate.h>
 #include <arm64/sysreg.h>
@@ -20,6 +21,7 @@
 
 #include "arm.h"
 #include "handle_exit.h"
+#include "qaaf.h"
 
 #define CREATE_TRACE_POINTS
 #include "trace.h"
@@ -741,9 +743,11 @@ long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
 
 static int __init kvm_s390_arm64_init(void)
 {
-	if (!sclp.has_aef)
+	if (!sclp.has_aef || !aef_usable())
 		return -ENODEV;
 
+	kvm_init_qaaf();
+
 	return kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 }
 
diff --git a/arch/s390/kvm/arm64/qaaf.c b/arch/s390/kvm/arm64/qaaf.c
new file mode 100644
index 000000000000..f6b1750aed68
--- /dev/null
+++ b/arch/s390/kvm/arm64/qaaf.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/kvm_host.h>
+#include <asm/aef.h>
+#include "qaaf.h"
+
+static struct qaaf_qmc_block qmc_sanitized;
+
+/**
+ * kvm_qaaf_qmc() - Get the sanitised QAAF QMC block
+ */
+struct qaaf_qmc_block *kvm_qaaf_qmc(void)
+{
+	return &qmc_sanitized;
+}
+
+void __init kvm_init_qaaf(void)
+{
+	qmc_sanitized = *aef_qmc();
+}
+
+#define _qaaf_reg_case(id) case SYS_##id: return qmc_sanitized.regs[QAAF_REG_##id]
+u64 kvm_qaaf_read_ftr_reg(u32 id)
+{
+	switch (id) {
+	_qaaf_reg_case(MIDR_EL1);
+	_qaaf_reg_case(MPIDR_EL1);
+	_qaaf_reg_case(REVIDR_EL1);
+	_qaaf_reg_case(ID_PFR0_EL1);
+	_qaaf_reg_case(ID_PFR1_EL1);
+	_qaaf_reg_case(ID_DFR0_EL1);
+	_qaaf_reg_case(ID_AFR0_EL1);
+	_qaaf_reg_case(ID_MMFR0_EL1);
+	_qaaf_reg_case(ID_MMFR1_EL1);
+	_qaaf_reg_case(ID_MMFR2_EL1);
+	_qaaf_reg_case(ID_MMFR3_EL1);
+	_qaaf_reg_case(ID_ISAR0_EL1);
+	_qaaf_reg_case(ID_ISAR1_EL1);
+	_qaaf_reg_case(ID_ISAR2_EL1);
+	_qaaf_reg_case(ID_ISAR3_EL1);
+	_qaaf_reg_case(ID_ISAR4_EL1);
+	_qaaf_reg_case(ID_ISAR5_EL1);
+	_qaaf_reg_case(ID_MMFR4_EL1);
+	_qaaf_reg_case(ID_ISAR6_EL1);
+	_qaaf_reg_case(MVFR0_EL1);
+	_qaaf_reg_case(MVFR1_EL1);
+	_qaaf_reg_case(MVFR2_EL1);
+	_qaaf_reg_case(ID_PFR2_EL1);
+	_qaaf_reg_case(ID_DFR1_EL1);
+	_qaaf_reg_case(ID_MMFR5_EL1);
+	_qaaf_reg_case(ID_AA64PFR0_EL1);
+	_qaaf_reg_case(ID_AA64PFR1_EL1);
+	_qaaf_reg_case(ID_AA64PFR2_EL1);
+	_qaaf_reg_case(ID_AA64ZFR0_EL1);
+	_qaaf_reg_case(ID_AA64SMFR0_EL1);
+	_qaaf_reg_case(ID_AA64FPFR0_EL1);
+	_qaaf_reg_case(ID_AA64DFR0_EL1);
+	_qaaf_reg_case(ID_AA64DFR1_EL1);
+	_qaaf_reg_case(ID_AA64DFR2_EL1);
+	_qaaf_reg_case(ID_AA64AFR0_EL1);
+	_qaaf_reg_case(ID_AA64AFR1_EL1);
+	_qaaf_reg_case(ID_AA64ISAR0_EL1);
+	_qaaf_reg_case(ID_AA64ISAR1_EL1);
+	_qaaf_reg_case(ID_AA64ISAR2_EL1);
+	_qaaf_reg_case(ID_AA64ISAR3_EL1);
+	_qaaf_reg_case(ID_AA64MMFR0_EL1);
+	_qaaf_reg_case(ID_AA64MMFR1_EL1);
+	_qaaf_reg_case(ID_AA64MMFR2_EL1);
+	_qaaf_reg_case(ID_AA64MMFR3_EL1);
+	_qaaf_reg_case(ID_AA64MMFR4_EL1);
+	_qaaf_reg_case(CNTFRQ_EL0);
+	_qaaf_reg_case(CTR_EL0);
+	_qaaf_reg_case(AIDR_EL1);
+	_qaaf_reg_case(ICH_VTR_EL2);
+	_qaaf_reg_case(PMMIR_EL1);
+	_qaaf_reg_case(PMCR_EL0);
+	_qaaf_reg_case(PMCEID0_EL0);
+	_qaaf_reg_case(PMCEID1_EL0);
+	default:
+		WARN(true, "Unknown feature register 0x%x\n", id);
+		return 0xbad1234bad;
+	}
+}
diff --git a/arch/s390/kvm/arm64/qaaf.h b/arch/s390/kvm/arm64/qaaf.h
new file mode 100644
index 000000000000..f1d50a9654b1
--- /dev/null
+++ b/arch/s390/kvm/arm64/qaaf.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef ARCH_S390_KVM_ARM64_QAAF_H
+#define ARCH_S390_KVM_ARM64_QAAF_H
+
+#include <asm/aef.h>
+
+__init void kvm_init_qaaf(void);
+struct qaaf_qmc_block *kvm_qaaf_qmc(void);
+u64 kvm_qaaf_read_ftr_reg(u32 id);
+
+#endif
diff --git a/arch/s390/tools/opcodes.txt b/arch/s390/tools/opcodes.txt
index 22fb9c500a56..bb4ba4038cb0 100644
--- a/arch/s390/tools/opcodes.txt
+++ b/arch/s390/tools/opcodes.txt
@@ -600,6 +600,7 @@ b9a7	stiasrm	RRE_R0
 b9aa	lptea	RRF_RURR2
 b9ab	essa	RRF_U0RR
 b9ac	irbm	RRE_RR
+b9ad	qaaf	RRE_R0
 b9ae	rrbm	RRE_RR
 b9af	pfmf	RRE_RR
 b9b0	cu14	RRF_U0RR

-- 
2.56.0