KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s

Currently, the {read,write}_sysreg_el*() accessors for accessing
particular ELs' sysregs in the presence of VHE rely on some local
hacks and define their system register encodings in a way that is
inconsistent with the core definitions in <asm/sysreg.h>.

As a result, it is necessary to add duplicate definitions for any
system register that already needs a definition in sysreg.h for
other reasons.

This is a bit of a maintenance headache, and the reasons for the
_el*() accessors working the way they do is a bit historical.

This patch gets rid of the shadow sysreg definitions in
<asm/kvm_hyp.h>, converts the _el*() accessors to use the core
__msr_s/__mrs_s interface, and converts all call sites to use the
standard sysreg #define names (i.e., upper case, with SYS_ prefix).

This patch will conflict heavily anyway, so the opportunity
to clean up some bad whitespace in the context of the changes is
taken.

The change exposes a few system registers that have no sysreg.h
definition, due to msr_s/mrs_s being used in place of msr/mrs:
additions are made in order to fill in the gaps.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://www.spinics.net/lists/kvm-arm/msg31717.html
[Rebased to v4.21-rc1]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
[Rebased to v5.2-rc5, changelog updates]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

3 files changed, 46 insertions, 55 deletions

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 8abca5df01e5..d69c1efc63e7 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -126,7 +126,7 @@ static inline unsigned long *__vcpu_elr_el1(const struct kvm_vcpu *vcpu)
 static inline unsigned long vcpu_read_elr_el1(const struct kvm_vcpu *vcpu)
 {
 	if (vcpu->arch.sysregs_loaded_on_cpu)
-		return read_sysreg_el1(elr);
+		return read_sysreg_el1(SYS_ELR);
 	else
 		return *__vcpu_elr_el1(vcpu);
 }
@@ -134,7 +134,7 @@ static inline unsigned long vcpu_read_elr_el1(const struct kvm_vcpu *vcpu)
 static inline void vcpu_write_elr_el1(const struct kvm_vcpu *vcpu, unsigned long v)
 {
 	if (vcpu->arch.sysregs_loaded_on_cpu)
-		write_sysreg_el1(v, elr);
+		write_sysreg_el1(v, SYS_ELR);
 	else
 		*__vcpu_elr_el1(vcpu) = v;
 }
@@ -186,7 +186,7 @@ static inline unsigned long vcpu_read_spsr(const struct kvm_vcpu *vcpu)
 		return vcpu_read_spsr32(vcpu);
 
 	if (vcpu->arch.sysregs_loaded_on_cpu)
-		return read_sysreg_el1(spsr);
+		return read_sysreg_el1(SYS_SPSR);
 	else
 		return vcpu_gp_regs(vcpu)->spsr[KVM_SPSR_EL1];
 }
@@ -199,7 +199,7 @@ static inline void vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long v)
 	}
 
 	if (vcpu->arch.sysregs_loaded_on_cpu)
-		write_sysreg_el1(v, spsr);
+		write_sysreg_el1(v, SYS_SPSR);
 	else
 		vcpu_gp_regs(vcpu)->spsr[KVM_SPSR_EL1] = v;
 }
@@ -465,13 +465,13 @@ static inline void kvm_skip_instr(struct kvm_vcpu *vcpu, bool is_wide_instr)
  */
 static inline void __hyp_text __kvm_skip_instr(struct kvm_vcpu *vcpu)
 {
-	*vcpu_pc(vcpu) = read_sysreg_el2(elr);
-	vcpu->arch.ctxt.gp_regs.regs.pstate = read_sysreg_el2(spsr);
+	*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
+	vcpu->arch.ctxt.gp_regs.regs.pstate = read_sysreg_el2(SYS_SPSR);
 
 	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
 
-	write_sysreg_el2(vcpu->arch.ctxt.gp_regs.regs.pstate, spsr);
-	write_sysreg_el2(*vcpu_pc(vcpu), elr);
+	write_sysreg_el2(vcpu->arch.ctxt.gp_regs.regs.pstate, SYS_SPSR);
+	write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
 }
 
 #endif /* __ARM64_KVM_EMULATE_H__ */
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 286f7e7e1be4..86825aa20852 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -18,7 +18,7 @@
 #define read_sysreg_elx(r,nvh,vh)					\
 	({								\
 		u64 reg;						\
-		asm volatile(ALTERNATIVE("mrs %0, " __stringify(r##nvh),\
+		asm volatile(ALTERNATIVE(__mrs_s("%0", r##nvh),	\
 					 __mrs_s("%0", r##vh),		\
 					 ARM64_HAS_VIRT_HOST_EXTN)	\
 			     : "=r" (reg));				\
@@ -28,7 +28,7 @@
 #define write_sysreg_elx(v,r,nvh,vh)					\
 	do {								\
 		u64 __val = (u64)(v);					\
-		asm volatile(ALTERNATIVE("msr " __stringify(r##nvh) ", %x0",\
+		asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"),	\
 					 __msr_s(r##vh, "%x0"),		\
 					 ARM64_HAS_VIRT_HOST_EXTN)	\
 					 : : "rZ" (__val));		\
@@ -37,55 +37,15 @@
 /*
  * Unified accessors for registers that have a different encoding
  * between VHE and non-VHE. They must be specified without their "ELx"
- * encoding.
+ * encoding, but with the SYS_ prefix, as defined in asm/sysreg.h.
  */
-#define read_sysreg_el2(r)						\
-	({								\
-		u64 reg;						\
-		asm volatile(ALTERNATIVE("mrs %0, " __stringify(r##_EL2),\
-					 "mrs %0, " __stringify(r##_EL1),\
-					 ARM64_HAS_VIRT_HOST_EXTN)	\
-			     : "=r" (reg));				\
-		reg;							\
-	})
-
-#define write_sysreg_el2(v,r)						\
-	do {								\
-		u64 __val = (u64)(v);					\
-		asm volatile(ALTERNATIVE("msr " __stringify(r##_EL2) ", %x0",\
-					 "msr " __stringify(r##_EL1) ", %x0",\
-					 ARM64_HAS_VIRT_HOST_EXTN)	\
-					 : : "rZ" (__val));		\
-	} while (0)
 
 #define read_sysreg_el0(r)	read_sysreg_elx(r, _EL0, _EL02)
 #define write_sysreg_el0(v,r)	write_sysreg_elx(v, r, _EL0, _EL02)
 #define read_sysreg_el1(r)	read_sysreg_elx(r, _EL1, _EL12)
 #define write_sysreg_el1(v,r)	write_sysreg_elx(v, r, _EL1, _EL12)
-
-/* The VHE specific system registers and their encoding */
-#define sctlr_EL12              sys_reg(3, 5, 1, 0, 0)
-#define cpacr_EL12              sys_reg(3, 5, 1, 0, 2)
-#define ttbr0_EL12              sys_reg(3, 5, 2, 0, 0)
-#define ttbr1_EL12              sys_reg(3, 5, 2, 0, 1)
-#define tcr_EL12                sys_reg(3, 5, 2, 0, 2)
-#define afsr0_EL12              sys_reg(3, 5, 5, 1, 0)
-#define afsr1_EL12              sys_reg(3, 5, 5, 1, 1)
-#define esr_EL12                sys_reg(3, 5, 5, 2, 0)
-#define far_EL12                sys_reg(3, 5, 6, 0, 0)
-#define mair_EL12               sys_reg(3, 5, 10, 2, 0)
-#define amair_EL12              sys_reg(3, 5, 10, 3, 0)
-#define vbar_EL12               sys_reg(3, 5, 12, 0, 0)
-#define contextidr_EL12         sys_reg(3, 5, 13, 0, 1)
-#define cntkctl_EL12            sys_reg(3, 5, 14, 1, 0)
-#define cntp_tval_EL02          sys_reg(3, 5, 14, 2, 0)
-#define cntp_ctl_EL02           sys_reg(3, 5, 14, 2, 1)
-#define cntp_cval_EL02          sys_reg(3, 5, 14, 2, 2)
-#define cntv_tval_EL02          sys_reg(3, 5, 14, 3, 0)
-#define cntv_ctl_EL02           sys_reg(3, 5, 14, 3, 1)
-#define cntv_cval_EL02          sys_reg(3, 5, 14, 3, 2)
-#define spsr_EL12               sys_reg(3, 5, 4, 0, 0)
-#define elr_EL12                sys_reg(3, 5, 4, 0, 1)
+#define read_sysreg_el2(r)	read_sysreg_elx(r, _EL2, _EL1)
+#define write_sysreg_el2(v,r)	write_sysreg_elx(v, r, _EL2, _EL1)
 
 /**
  * hyp_alternate_select - Generates patchable code sequences that are
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index cd7f7ce1a56a..852cc113de7c 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -191,6 +191,9 @@
 #define SYS_APGAKEYLO_EL1		sys_reg(3, 0, 2, 3, 0)
 #define SYS_APGAKEYHI_EL1		sys_reg(3, 0, 2, 3, 1)
 
+#define SYS_SPSR_EL1			sys_reg(3, 0, 4, 0, 0)
+#define SYS_ELR_EL1			sys_reg(3, 0, 4, 0, 1)
+
 #define SYS_ICC_PMR_EL1			sys_reg(3, 0, 4, 6, 0)
 
 #define SYS_AFSR0_EL1			sys_reg(3, 0, 5, 1, 0)
@@ -382,6 +385,9 @@
 #define SYS_CNTP_CTL_EL0		sys_reg(3, 3, 14, 2, 1)
 #define SYS_CNTP_CVAL_EL0		sys_reg(3, 3, 14, 2, 2)
 
+#define SYS_CNTV_CTL_EL0		sys_reg(3, 3, 14, 3, 1)
+#define SYS_CNTV_CVAL_EL0		sys_reg(3, 3, 14, 3, 2)
+
 #define SYS_AARCH32_CNTP_TVAL		sys_reg(0, 0, 14, 2, 0)
 #define SYS_AARCH32_CNTP_CTL		sys_reg(0, 0, 14, 2, 1)
 #define SYS_AARCH32_CNTP_CVAL		sys_reg(0, 2, 0, 14, 0)
@@ -392,14 +398,17 @@
 #define __TYPER_CRm(n)			(0xc | (((n) >> 3) & 0x3))
 #define SYS_PMEVTYPERn_EL0(n)		sys_reg(3, 3, 14, __TYPER_CRm(n), __PMEV_op2(n))
 
-#define SYS_PMCCFILTR_EL0		sys_reg (3, 3, 14, 15, 7)
+#define SYS_PMCCFILTR_EL0		sys_reg(3, 3, 14, 15, 7)
 
 #define SYS_ZCR_EL2			sys_reg(3, 4, 1, 2, 0)
-
 #define SYS_DACR32_EL2			sys_reg(3, 4, 3, 0, 0)
+#define SYS_SPSR_EL2			sys_reg(3, 4, 4, 0, 0)
+#define SYS_ELR_EL2			sys_reg(3, 4, 4, 0, 1)
 #define SYS_IFSR32_EL2			sys_reg(3, 4, 5, 0, 1)
+#define SYS_ESR_EL2			sys_reg(3, 4, 5, 2, 0)
 #define SYS_VSESR_EL2			sys_reg(3, 4, 5, 2, 3)
 #define SYS_FPEXC32_EL2			sys_reg(3, 4, 5, 3, 0)
+#define SYS_FAR_EL2			sys_reg(3, 4, 6, 0, 0)
 
 #define SYS_VDISR_EL2			sys_reg(3, 4, 12, 1,  1)
 #define __SYS__AP0Rx_EL2(x)		sys_reg(3, 4, 12, 8, x)
@@ -444,7 +453,29 @@
 #define SYS_ICH_LR15_EL2		__SYS__LR8_EL2(7)
 
 /* VHE encodings for architectural EL0/1 system registers */
+#define SYS_SCTLR_EL12			sys_reg(3, 5, 1, 0, 0)
+#define SYS_CPACR_EL12			sys_reg(3, 5, 1, 0, 2)
 #define SYS_ZCR_EL12			sys_reg(3, 5, 1, 2, 0)
+#define SYS_TTBR0_EL12			sys_reg(3, 5, 2, 0, 0)
+#define SYS_TTBR1_EL12			sys_reg(3, 5, 2, 0, 1)
+#define SYS_TCR_EL12			sys_reg(3, 5, 2, 0, 2)
+#define SYS_SPSR_EL12			sys_reg(3, 5, 4, 0, 0)
+#define SYS_ELR_EL12			sys_reg(3, 5, 4, 0, 1)
+#define SYS_AFSR0_EL12			sys_reg(3, 5, 5, 1, 0)
+#define SYS_AFSR1_EL12			sys_reg(3, 5, 5, 1, 1)
+#define SYS_ESR_EL12			sys_reg(3, 5, 5, 2, 0)
+#define SYS_FAR_EL12			sys_reg(3, 5, 6, 0, 0)
+#define SYS_MAIR_EL12			sys_reg(3, 5, 10, 2, 0)
+#define SYS_AMAIR_EL12			sys_reg(3, 5, 10, 3, 0)
+#define SYS_VBAR_EL12			sys_reg(3, 5, 12, 0, 0)
+#define SYS_CONTEXTIDR_EL12		sys_reg(3, 5, 13, 0, 1)
+#define SYS_CNTKCTL_EL12		sys_reg(3, 5, 14, 1, 0)
+#define SYS_CNTP_TVAL_EL02		sys_reg(3, 5, 14, 2, 0)
+#define SYS_CNTP_CTL_EL02		sys_reg(3, 5, 14, 2, 1)
+#define SYS_CNTP_CVAL_EL02		sys_reg(3, 5, 14, 2, 2)
+#define SYS_CNTV_TVAL_EL02		sys_reg(3, 5, 14, 3, 0)
+#define SYS_CNTV_CTL_EL02		sys_reg(3, 5, 14, 3, 1)
+#define SYS_CNTV_CVAL_EL02		sys_reg(3, 5, 14, 3, 2)
 
 /* Common SCTLR_ELx flags. */
 #define SCTLR_ELx_DSSBS	(_BITUL(44))