[PATCH v1 2/7] KVM: arm64: Specialize deactivate fpsimd/sve traps on guest trap

[Fuad Tabba]

The code for deactivating traps, to be able to update the
fpsimd/sve registers, is the only code in switch.h that is n/vhe
specific, i.e., behaves differently whether it's running in
vhe/nvhe. Move it to specialized functions in switch.c like other
mode-specific code.

This is needed for subsequent patches, since the logic for
deciding which traps to enable/disable will diverge between
n/vhe.

No functional change intended.

Signed-off-by: Fuad Tabba <tabba at google.com>
---
 arch/arm64/kvm/hyp/include/hyp/switch.h | 18 +++---------------
 arch/arm64/kvm/hyp/nvhe/switch.c        | 21 +++++++++++++++++++++
 arch/arm64/kvm/hyp/vhe/switch.c         | 11 +++++++++++
 3 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index a92566f36022..890388c17c3e 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -320,6 +320,8 @@ static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu)
 	write_sysreg_el1(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR);
 }
 
+static void __deactivate_fpsimd_sve_traps(struct kvm_vcpu *vcpu);
+
 /*
  * We trap the first access to the FP/SIMD to save the host context and
  * restore the guest context lazily.
@@ -330,7 +332,6 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
 {
 	bool sve_guest;
 	u8 esr_ec;
-	u64 reg;
 
 	if (!system_supports_fpsimd())
 		return false;
@@ -353,20 +354,7 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
 	/* Valid trap.  Switch the context: */
 
 	/* First disable enough traps to allow us to update the registers */
-	if (has_vhe() || has_hvhe()) {
-		reg = CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN;
-		if (sve_guest)
-			reg |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
-
-		sysreg_clear_set(cpacr_el1, 0, reg);
-	} else {
-		reg = CPTR_EL2_TFP;
-		if (sve_guest)
-			reg |= CPTR_EL2_TZ;
-
-		sysreg_clear_set(cptr_el2, reg, 0);
-	}
-	isb();
+	__deactivate_fpsimd_sve_traps(vcpu);
 
 	/* Write out the host state if it's in the registers */
 	if (host_owns_fp_regs())
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 6758cd905570..2b5af10cdf1d 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -112,6 +112,27 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
 	write_sysreg(__kvm_hyp_host_vector, vbar_el2);
 }
 
+static void __deactivate_fpsimd_sve_traps(struct kvm_vcpu *vcpu)
+{
+	bool clear_sve_traps = vcpu_has_sve(vcpu);
+	u64 reg;
+
+	if (has_hvhe()) {
+		reg = CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN;
+		if (clear_sve_traps)
+			reg |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
+
+		sysreg_clear_set(cpacr_el1, 0, reg);
+	} else {
+		reg = CPTR_EL2_TFP;
+		if (clear_sve_traps)
+			reg |= CPTR_EL2_TZ;
+
+		sysreg_clear_set(cptr_el2, reg, 0);
+	}
+	isb();
+}
+
 /* Save VGICv3 state on non-VHE systems */
 static void __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
 {
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index d7af5f46f22a..740360065d7d 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -209,6 +209,17 @@ void kvm_vcpu_put_vhe(struct kvm_vcpu *vcpu)
 	host_data_ptr(host_ctxt)->__hyp_running_vcpu = NULL;
 }
 
+static void __deactivate_fpsimd_sve_traps(struct kvm_vcpu *vcpu)
+{
+	u64 reg = CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN;
+
+	if (vcpu_has_sve(vcpu))
+		reg |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
+
+	sysreg_clear_set(cpacr_el1, 0, reg);
+	isb();
+}
+
 static bool kvm_hyp_handle_eret(struct kvm_vcpu *vcpu, u64 *exit_code)
 {
 	u64 esr = kvm_vcpu_get_esr(vcpu);
-- 
2.45.0.rc1.225.g2a3ae87e7f-goog