KVM: arm64: Make vcpu const in vcpu_read_sys_reg

christofferdall-arm · Marc Zyngier · commit da6f16662a6e · 2018-12-19T17:47:07.000Z
vcpu_read_sys_reg should not be modifying the VCPU structure.
Eventually, to handle EL2 sysregs for nested virtualization, we will
call vcpu_read_sys_reg from places that have a const vcpu pointer, which
will complain about the lack of the const modifier on the read path.

Signed-off-by: Christoffer Dall &lt;christoffer.dall@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
@@ -319,7 +319,7 @@ struct kvm_vcpu_arch {
  */
 #define __vcpu_sys_reg(v,r)	((v)->arch.ctxt.sys_regs[(r)])
 
-u64 vcpu_read_sys_reg(struct kvm_vcpu *vcpu, int reg);
+u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg);
 void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg);
 
 /*
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
@@ -76,7 +76,7 @@ static bool write_to_read_only(struct kvm_vcpu *vcpu,
 	return false;
 }
 
-u64 vcpu_read_sys_reg(struct kvm_vcpu *vcpu, int reg)
+u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
 {
 	if (!vcpu->arch.sysregs_loaded_on_cpu)
 		goto immediate_read;

Original file line number	Diff line number	Diff line change
`@@ -76,7 +76,7 @@ static bool write_to_read_only(struct kvm_vcpu *vcpu,`
`76`	`76`	`return false;`
`77`	`77`	`}`
`78`	`78`
`79`		`-u64 vcpu_read_sys_reg(struct kvm_vcpu *vcpu, int reg)`
	`79`	`+u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)`
`80`	`80`	`{`
`81`	`81`	`if (!vcpu->arch.sysregs_loaded_on_cpu)`
`82`	`82`	`goto immediate_read;`