Merge branch kvm-arm64/fpmr into kvmarm-master/next

* kvm-arm64/fpmr:
  : .
  : Add FP8 support to the KVM/arm64 floating point handling.
  :
  : This includes new ID registers (ID_AA64PFR2_EL1 ID_AA64FPFR0_EL1)
  : being made visible to guests, as well as a new confrol register
  : (FPMR) which gets context-switched.
  : .
  KVM: arm64: Expose ID_AA64PFR2_EL1 to userspace and guests
  KVM: arm64: Enable FP8 support when available and configured
  KVM: arm64: Expose ID_AA64FPFR0_EL1 as a writable ID reg
  KVM: arm64: Honor trap routing for FPMR
  KVM: arm64: Add save/restore support for FPMR
  KVM: arm64: Move FPMR into the sysreg array
  KVM: arm64: Add predicate for FPMR support in a VM
  KVM: arm64: Move SVCR into the sysreg array

Signed-off-by: Marc Zyngier <maz@kernel.org>

4 files changed, 24 insertions, 0 deletions

diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 37ff87d782b6..46d52e8a3df3 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -403,6 +403,9 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
 	else
 		__fpsimd_restore_state(&vcpu->arch.ctxt.fp_regs);
 
+	if (kvm_has_fpmr(kern_hyp_va(vcpu->kvm)))
+		write_sysreg_s(__vcpu_sys_reg(vcpu, FPMR), SYS_FPMR);
+
 	/* Skip restoring fpexc32 for AArch64 guests */
 	if (!(read_sysreg(hcr_el2) & HCR_RW))
 		write_sysreg(__vcpu_sys_reg(vcpu, FPEXC32_EL2), fpexc32_el2);
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index f43d845f3c4e..87692b566d90 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -62,6 +62,8 @@ static void fpsimd_sve_flush(void)
 
 static void fpsimd_sve_sync(struct kvm_vcpu *vcpu)
 {
+	bool has_fpmr;
+
 	if (!guest_owns_fp_regs())
 		return;
 
@@ -73,11 +75,18 @@ static void fpsimd_sve_sync(struct kvm_vcpu *vcpu)
 	else
 		__fpsimd_save_state(&vcpu->arch.ctxt.fp_regs);
 
+	has_fpmr = kvm_has_fpmr(kern_hyp_va(vcpu->kvm));
+	if (has_fpmr)
+		__vcpu_sys_reg(vcpu, FPMR) = read_sysreg_s(SYS_FPMR);
+
 	if (system_supports_sve())
 		__hyp_sve_restore_host();
 	else
 		__fpsimd_restore_state(*host_data_ptr(fpsimd_state));
 
+	if (has_fpmr)
+		write_sysreg_s(*host_data_ptr(fpmr), SYS_FPMR);
+
 	*host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED;
 }
 
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 8f5c56d5b1cd..cc69106734ca 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -197,6 +197,15 @@ static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu)
 	} else {
 		__fpsimd_save_state(*host_data_ptr(fpsimd_state));
 	}
+
+	if (kvm_has_fpmr(kern_hyp_va(vcpu->kvm))) {
+		u64 val = read_sysreg_s(SYS_FPMR);
+
+		if (unlikely(is_protected_kvm_enabled()))
+			*host_data_ptr(fpmr) = val;
+		else
+			**host_data_ptr(fpmr_ptr) = val;
+	}
 }
 
 static const exit_handler_fn hyp_exit_handlers[] = {
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 77010b76c150..80581b1c3995 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -312,6 +312,9 @@ static bool kvm_hyp_handle_eret(struct kvm_vcpu *vcpu, u64 *exit_code)
 static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu)
 {
 	__fpsimd_save_state(*host_data_ptr(fpsimd_state));
+
+	if (kvm_has_fpmr(vcpu->kvm))
+		**host_data_ptr(fpmr_ptr) = read_sysreg_s(SYS_FPMR);
 }
 
 static bool kvm_hyp_handle_tlbi_el2(struct kvm_vcpu *vcpu, u64 *exit_code)