[PATCH v4 07/29] KVM: arm64: Save/restore POE registers

[Joey Gouly <joey.gouly@arm.com>]

Define the new system registers that POE introduces and context switch them.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
---
 arch/arm64/include/asm/kvm_host.h          |  4 +++
 arch/arm64/include/asm/vncr_mapping.h      |  1 +
 arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 29 ++++++++++++++++++++++
 arch/arm64/kvm/sys_regs.c                  |  8 ++++--
 4 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 9e8a496fb284..28042da0befd 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -419,6 +419,8 @@ enum vcpu_sysreg {
 	GCR_EL1,	/* Tag Control Register */
 	TFSRE0_EL1,	/* Tag Fault Status Register (EL0) */
 
+	POR_EL0,	/* Permission Overlay Register 0 (EL0) */
+
 	/* 32bit specific registers. */
 	DACR32_EL2,	/* Domain Access Control Register */
 	IFSR32_EL2,	/* Instruction Fault Status Register */
@@ -489,6 +491,8 @@ enum vcpu_sysreg {
 	VNCR(PIR_EL1),	 /* Permission Indirection Register 1 (EL1) */
 	VNCR(PIRE0_EL1), /*  Permission Indirection Register 0 (EL1) */
 
+	VNCR(POR_EL1),	/* Permission Overlay Register 1 (EL1) */
+
 	VNCR(HFGRTR_EL2),
 	VNCR(HFGWTR_EL2),
 	VNCR(HFGITR_EL2),
diff --git a/arch/arm64/include/asm/vncr_mapping.h b/arch/arm64/include/asm/vncr_mapping.h
index df2c47c55972..06f8ec0906a6 100644
--- a/arch/arm64/include/asm/vncr_mapping.h
+++ b/arch/arm64/include/asm/vncr_mapping.h
@@ -52,6 +52,7 @@
 #define VNCR_PIRE0_EL1		0x290
 #define VNCR_PIRE0_EL2		0x298
 #define VNCR_PIR_EL1		0x2A0
+#define VNCR_POR_EL1		0x2A8
 #define VNCR_ICH_LR0_EL2        0x400
 #define VNCR_ICH_LR1_EL2        0x408
 #define VNCR_ICH_LR2_EL2        0x410
diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
index 4be6a7fa0070..1c9536557bae 100644
--- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
+++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
@@ -16,9 +16,15 @@
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 
+static inline bool ctxt_has_s1poe(struct kvm_cpu_context *ctxt);
+
 static inline void __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
 {
 	ctxt_sys_reg(ctxt, MDSCR_EL1)	= read_sysreg(mdscr_el1);
+
+	// POR_EL0 can affect uaccess, so must be saved/restored early.
+	if (ctxt_has_s1poe(ctxt))
+		ctxt_sys_reg(ctxt, POR_EL0)	= read_sysreg_s(SYS_POR_EL0);
 }
 
 static inline void __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
@@ -55,6 +61,17 @@ static inline bool ctxt_has_s1pie(struct kvm_cpu_context *ctxt)
 	return kvm_has_feat(kern_hyp_va(vcpu->kvm), ID_AA64MMFR3_EL1, S1PIE, IMP);
 }
 
+static inline bool ctxt_has_s1poe(struct kvm_cpu_context *ctxt)
+{
+	struct kvm_vcpu *vcpu;
+
+	if (!system_supports_poe())
+		return false;
+
+	vcpu = ctxt_to_vcpu(ctxt);
+	return kvm_has_feat(kern_hyp_va(vcpu->kvm), ID_AA64MMFR3_EL1, S1POE, IMP);
+}
+
 static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 {
 	ctxt_sys_reg(ctxt, SCTLR_EL1)	= read_sysreg_el1(SYS_SCTLR);
@@ -77,6 +94,10 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
 		ctxt_sys_reg(ctxt, PIR_EL1)	= read_sysreg_el1(SYS_PIR);
 		ctxt_sys_reg(ctxt, PIRE0_EL1)	= read_sysreg_el1(SYS_PIRE0);
 	}
+
+	if (ctxt_has_s1poe(ctxt))
+		ctxt_sys_reg(ctxt, POR_EL1)	= read_sysreg_el1(SYS_POR);
+
 	ctxt_sys_reg(ctxt, PAR_EL1)	= read_sysreg_par();
 	ctxt_sys_reg(ctxt, TPIDR_EL1)	= read_sysreg(tpidr_el1);
 
@@ -107,6 +128,10 @@ static inline void __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
 static inline void __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
 {
 	write_sysreg(ctxt_sys_reg(ctxt, MDSCR_EL1),  mdscr_el1);
+
+	// POR_EL0 can affect uaccess, so must be saved/restored early.
+	if (ctxt_has_s1poe(ctxt))
+		write_sysreg_s(ctxt_sys_reg(ctxt, POR_EL0),	SYS_POR_EL0);
 }
 
 static inline void __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
@@ -153,6 +178,10 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
 		write_sysreg_el1(ctxt_sys_reg(ctxt, PIR_EL1),	SYS_PIR);
 		write_sysreg_el1(ctxt_sys_reg(ctxt, PIRE0_EL1),	SYS_PIRE0);
 	}
+
+	if (ctxt_has_s1poe(ctxt))
+		write_sysreg_el1(ctxt_sys_reg(ctxt, POR_EL1),	SYS_POR);
+
 	write_sysreg(ctxt_sys_reg(ctxt, PAR_EL1),	par_el1);
 	write_sysreg(ctxt_sys_reg(ctxt, TPIDR_EL1),	tpidr_el1);
 
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index c9f4f387155f..be04fae35afb 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2423,6 +2423,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_MAIR_EL1), access_vm_reg, reset_unknown, MAIR_EL1 },
 	{ SYS_DESC(SYS_PIRE0_EL1), NULL, reset_unknown, PIRE0_EL1 },
 	{ SYS_DESC(SYS_PIR_EL1), NULL, reset_unknown, PIR_EL1 },
+	{ SYS_DESC(SYS_POR_EL1), NULL, reset_unknown, POR_EL1 },
 	{ SYS_DESC(SYS_AMAIR_EL1), access_vm_reg, reset_amair_el1, AMAIR_EL1 },
 
 	{ SYS_DESC(SYS_LORSA_EL1), trap_loregion },
@@ -2506,6 +2507,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	  .access = access_pmovs, .reg = PMOVSSET_EL0,
 	  .get_user = get_pmreg, .set_user = set_pmreg },
 
+	{ SYS_DESC(SYS_POR_EL0), NULL, reset_unknown, POR_EL0 },
 	{ SYS_DESC(SYS_TPIDR_EL0), NULL, reset_unknown, TPIDR_EL0 },
 	{ SYS_DESC(SYS_TPIDRRO_EL0), NULL, reset_unknown, TPIDRRO_EL0 },
 	{ SYS_DESC(SYS_TPIDR2_EL0), undef_access },
@@ -4057,8 +4059,6 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
 	kvm->arch.fgu[HFGxTR_GROUP] = (HFGxTR_EL2_nAMAIR2_EL1		|
 				       HFGxTR_EL2_nMAIR2_EL1		|
 				       HFGxTR_EL2_nS2POR_EL1		|
-				       HFGxTR_EL2_nPOR_EL1		|
-				       HFGxTR_EL2_nPOR_EL0		|
 				       HFGxTR_EL2_nACCDATA_EL1		|
 				       HFGxTR_EL2_nSMPRI_EL1_MASK	|
 				       HFGxTR_EL2_nTPIDR2_EL0_MASK);
@@ -4093,6 +4093,10 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
 		kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nPIRE0_EL1 |
 						HFGxTR_EL2_nPIR_EL1);
 
+	if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, S1POE, IMP))
+		kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nPOR_EL1 |
+						HFGxTR_EL2_nPOR_EL0);
+
 	if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, AMU, IMP))
 		kvm->arch.fgu[HAFGRTR_GROUP] |= ~(HAFGRTR_EL2_RES0 |
 						  HAFGRTR_EL2_RES1);
-- 
2.25.1