KVM: arm64: Move skip_host_instruction to adjust_pc.h

Move function for skipping host instruction in the host trap handler to
a header file containing analogical helpers for guests.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201208142452.87237-7-dbrazdil@google.com

diff --git a/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h b/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
index b1f6092..6171635 100644 (file)
--- a/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
+++ b/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
@@ -59,4 +59,13 @@ static inline void __adjust_pc(struct kvm_vcpu *vcpu)
        }
 }
 
+/*
+ * Skip an instruction while host sysregs are live.
+ * Assumes host is always 64-bit.
+ */
+static inline void kvm_skip_host_instr(void)
+{
+       write_sysreg_el2(read_sysreg_el2(SYS_ELR) + 4, SYS_ELR);
+}
+
 #endif

diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index bde658d..a906f9e 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -157,11 +157,6 @@ static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt)
        __kvm_hyp_host_forward_smc(host_ctxt);
 }
 
-static void skip_host_instruction(void)
-{
-       write_sysreg_el2(read_sysreg_el2(SYS_ELR) + 4, SYS_ELR);
-}
-
 static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
 {
        bool handled;
@@ -170,11 +165,8 @@ static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
        if (!handled)
                default_host_smc_handler(host_ctxt);
 
-       /*
-        * Unlike HVC, the return address of an SMC is the instruction's PC.
-        * Move the return address past the instruction.
-        */
-       skip_host_instruction();
+       /* SMC was trapped, move ELR past the current PC. */
+       kvm_skip_host_instr();
 }
 
 void handle_trap(struct kvm_cpu_context *host_ctxt)