arm64: KVM: Switch vgic save/restore to alternative_insn

So far, we configured the world-switch by having a small array
of pointers to the save and restore functions, depending on the
GIC used on the platform.

Loading these values each time is a bit silly (they never change),
and it makes sense to rely on the instruction patching instead.

This leads to a nice cleanup of the code.

Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index d71607c16601b6b1e1a595e32562195ccd63f5b1..e896d2c196e63b79365e6f637c7b697c56c48f71 100644 (file)
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -218,11 +218,6 @@ static inline int kvm_arch_dev_ioctl_check_extension(long ext)
        return 0;
 }
 
-static inline void vgic_arch_setup(const struct vgic_params *vgic)
-{
-       BUG_ON(vgic->type != VGIC_V2);
-}
-
 int kvm_perf_init(void);
 int kvm_perf_teardown(void);
 

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 4f7310fa77f01acd8084b16e52f9df3fce8c4091..d13bc5eb688cbf593cce4ff6d6887495620e47a8 100644 (file)
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -132,11 +132,6 @@ extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
 
 extern u64 __vgic_v3_get_ich_vtr_el2(void);
 
-extern char __save_vgic_v2_state[];
-extern char __restore_vgic_v2_state[];
-extern char __save_vgic_v3_state[];
-extern char __restore_vgic_v3_state[];
-
 #endif
 
 #endif /* __ARM_KVM_ASM_H__ */

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index f0f58c9beec0e87c8c7eefa7a8ba52ba518e07c3..2709db2a7eac78a49fc75c072810b9ac41cc9e0a 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -221,29 +221,6 @@ struct vgic_sr_vectors {
        void    *restore_vgic;
 };
 
-static inline void vgic_arch_setup(const struct vgic_params *vgic)
-{
-       extern struct vgic_sr_vectors __vgic_sr_vectors;
-
-       switch(vgic->type)
-       {
-       case VGIC_V2:
-               __vgic_sr_vectors.save_vgic     = __save_vgic_v2_state;
-               __vgic_sr_vectors.restore_vgic  = __restore_vgic_v2_state;
-               break;
-
-#ifdef CONFIG_ARM_GIC_V3
-       case VGIC_V3:
-               __vgic_sr_vectors.save_vgic     = __save_vgic_v3_state;
-               __vgic_sr_vectors.restore_vgic  = __restore_vgic_v3_state;
-               break;
-#endif
-
-       default:
-               BUG();
-       }
-}
-
 static inline void kvm_arch_hardware_disable(void) {}
 static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}

diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index da675cc5dfaeef4e4e0dfb954c0fe26a46238615..c99701a34d7b3c9238c80e1e4ebbaeba6e3488c3 100644 (file)
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -127,7 +127,6 @@ int main(void)
   DEFINE(VCPU_VGIC_CPU,                offsetof(struct kvm_vcpu, arch.vgic_cpu));
   DEFINE(VGIC_SAVE_FN,         offsetof(struct vgic_sr_vectors, save_vgic));
   DEFINE(VGIC_RESTORE_FN,      offsetof(struct vgic_sr_vectors, restore_vgic));
-  DEFINE(VGIC_SR_VECTOR_SZ,    sizeof(struct vgic_sr_vectors));
   DEFINE(VGIC_V2_CPU_HCR,      offsetof(struct vgic_cpu, vgic_v2.vgic_hcr));
   DEFINE(VGIC_V2_CPU_VMCR,     offsetof(struct vgic_cpu, vgic_v2.vgic_vmcr));
   DEFINE(VGIC_V2_CPU_MISR,     offsetof(struct vgic_cpu, vgic_v2.vgic_misr));

diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 5befd010e23255c151999334daf9336912b4b664..f1f6d902b772489e0907ecb26c62c01a2e1bacc1 100644 (file)
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -17,8 +17,10 @@
 
 #include <linux/linkage.h>
 
+#include <asm/alternative.h>
 #include <asm/asm-offsets.h>
 #include <asm/assembler.h>
+#include <asm/cpufeature.h>
 #include <asm/debug-monitors.h>
 #include <asm/esr.h>
 #include <asm/fpsimdmacros.h>
@@ -808,10 +810,7 @@
  * Call into the vgic backend for state saving
  */
 .macro save_vgic_state
-       adr     x24, __vgic_sr_vectors
-       ldr     x24, [x24, VGIC_SAVE_FN]
-       kern_hyp_va     x24
-       blr     x24
+       alternative_insn "bl __save_vgic_v2_state", "bl __save_vgic_v3_state", ARM64_HAS_SYSREG_GIC_CPUIF
        mrs     x24, hcr_el2
        mov     x25, #HCR_INT_OVERRIDE
        neg     x25, x25
@@ -828,10 +827,7 @@
        orr     x24, x24, #HCR_INT_OVERRIDE
        orr     x24, x24, x25
        msr     hcr_el2, x24
-       adr     x24, __vgic_sr_vectors
-       ldr     x24, [x24, #VGIC_RESTORE_FN]
-       kern_hyp_va     x24
-       blr     x24
+       alternative_insn "bl __restore_vgic_v2_state", "bl __restore_vgic_v3_state", ARM64_HAS_SYSREG_GIC_CPUIF
 .endm
 
 .macro save_timer_state
@@ -1062,12 +1058,6 @@ ENTRY(__kvm_flush_vm_context)
        ret
 ENDPROC(__kvm_flush_vm_context)
 
-       // struct vgic_sr_vectors __vgi_sr_vectors;
-       .align 3
-ENTRY(__vgic_sr_vectors)
-       .skip   VGIC_SR_VECTOR_SZ
-ENDPROC(__vgic_sr_vectors)
-
 __kvm_hyp_panic:
        // Guess the context by looking at VTTBR:
        // If zero, then we're already a host.

diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 78fb8201014f74f2172baf8a48acc5173a450f4d..003ba74e48d1796bbbb7c38f5fb37fe6a229cd03 100644 (file)
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -2128,9 +2128,6 @@ int kvm_vgic_hyp_init(void)
                goto out_free_irq;
        }
 
-       /* Callback into for arch code for setup */
-       vgic_arch_setup(vgic);
-
        on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
 
        return 0;