[PATCH v4 7/9] KVM: arm64: pkvm: Add a generic synchronous exception injection primitive

[Marc Zyngier <maz@kernel.org>]

Similarly to the "classic" KVM code, pKVM doesn't have an "anything
goes" synchronous exception injection primitive.

Carve one out of the UNDEF injection code.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/hyp/nvhe/sys_regs.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
index 4db0562f5bfa4..b197f3eb272c1 100644
--- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c
+++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
@@ -243,16 +243,15 @@ static u64 pvm_calc_id_reg(const struct kvm_vcpu *vcpu, u32 id)
 	}
 }
 
-/*
- * Inject an unknown/undefined exception to an AArch64 guest while most of its
- * sysregs are live.
- */
-static void inject_undef64(struct kvm_vcpu *vcpu)
+static void inject_sync64(struct kvm_vcpu *vcpu, u64 esr)
 {
-	u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);
-
 	*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
 	*vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR);
+
+	/*
+	 * Make sure we have the latest update to VBAR_EL1, as pKVM
+	 * handles traps very early, before sysregs are resync'ed
+	 */
 	__vcpu_assign_sys_reg(vcpu, VBAR_EL1, read_sysreg_el1(SYS_VBAR));
 
 	kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
@@ -265,6 +264,15 @@ static void inject_undef64(struct kvm_vcpu *vcpu)
 	write_sysreg_el2(*vcpu_cpsr(vcpu), SYS_SPSR);
 }
 
+/*
+ * Inject an unknown/undefined exception to an AArch64 guest while most of its
+ * sysregs are live.
+ */
+static void inject_undef64(struct kvm_vcpu *vcpu)
+{
+	inject_sync64(vcpu, (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT));
+}
+
 static u64 read_id_reg(const struct kvm_vcpu *vcpu,
 		       struct sys_reg_desc const *r)
 {
-- 
2.47.3