KVM: arm/arm64: Cleanup MMIO handling

Our MMIO handling is a bit odd, in the sense that it uses an
intermediate per-vcpu structure to store the various decoded
information that describe the access.

But the same information is readily available in the HSR/ESR_EL2
field, and we actually use this field to populate the structure.

Let's simplify the whole thing by getting rid of the superfluous
structure and save a (tiny) bit of space in the vcpu structure.

[32bit fix courtesy of Olof Johansson <olof@lixom.net>]
Signed-off-by: Marc Zyngier <maz@kernel.org>

7 files changed, 20 insertions, 68 deletions

diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index 08d9805f613b..3944305e81df 100644
--- a/arch/arm/include/asm/kvm_emulate.h
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -9,7 +9,6 @@
 
 #include <linux/kvm_host.h>
 #include <asm/kvm_asm.h>
-#include <asm/kvm_mmio.h>
 #include <asm/kvm_arm.h>
 #include <asm/cputype.h>
 
@@ -220,7 +219,7 @@ static inline bool kvm_vcpu_dabt_is_cm(struct kvm_vcpu *vcpu)
 }
 
 /* Get Access Size from a data abort */
-static inline int kvm_vcpu_dabt_get_as(struct kvm_vcpu *vcpu)
+static inline unsigned int kvm_vcpu_dabt_get_as(struct kvm_vcpu *vcpu)
 {
 	switch ((kvm_vcpu_get_hsr(vcpu) >> 22) & 0x3) {
 	case 0:
@@ -231,7 +230,7 @@ static inline int kvm_vcpu_dabt_get_as(struct kvm_vcpu *vcpu)
 		return 4;
 	default:
 		kvm_err("Hardware is weird: SAS 0b11 is reserved\n");
-		return -EFAULT;
+		return 4;
 	}
 }
 
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 556cd818eccf..bd2233805d99 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -14,7 +14,6 @@
 #include <asm/cputype.h>
 #include <asm/kvm.h>
 #include <asm/kvm_asm.h>
-#include <asm/kvm_mmio.h>
 #include <asm/fpstate.h>
 #include <kvm/arm_arch_timer.h>
 
@@ -202,9 +201,6 @@ struct kvm_vcpu_arch {
 	 /* Don't run the guest (internal implementation need) */
 	bool pause;
 
-	/* IO related fields */
-	struct kvm_decode mmio_decode;
-
 	/* Cache some mmu pages needed inside spinlock regions */
 	struct kvm_mmu_memory_cache mmu_page_cache;
 
@@ -300,6 +296,14 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 static inline void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run,
 				     int exception_index) {}
 
+/* MMIO helpers */
+void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
+unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);
+
+int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
+		 phys_addr_t fault_ipa);
+
 static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr,
 				       unsigned long hyp_stack_ptr,
 				       unsigned long vector_ptr)
diff --git a/arch/arm/include/asm/kvm_hyp.h b/arch/arm/include/asm/kvm_hyp.h
index 40e9034db601..3c1b55ecc578 100644
--- a/arch/arm/include/asm/kvm_hyp.h
+++ b/arch/arm/include/asm/kvm_hyp.h
@@ -10,6 +10,7 @@
 #include <linux/compiler.h>
 #include <linux/kvm_host.h>
 #include <asm/cp15.h>
+#include <asm/kvm_arm.h>
 #include <asm/vfp.h>
 
 #define __hyp_text __section(.hyp.text) notrace
diff --git a/arch/arm/include/asm/kvm_mmio.h b/arch/arm/include/asm/kvm_mmio.h
deleted file mode 100644
index 32fbf82e3ebc..000000000000
--- a/arch/arm/include/asm/kvm_mmio.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2012 - Virtual Open Systems and Columbia University
- * Author: Christoffer Dall <c.dall@virtualopensystems.com>
- */
-
-#ifndef __ARM_KVM_MMIO_H__
-#define __ARM_KVM_MMIO_H__
-
-#include <linux/kvm_host.h>
-#include <asm/kvm_asm.h>
-#include <asm/kvm_arm.h>
-
-struct kvm_decode {
-	unsigned long rt;
-	bool sign_extend;
-	/* Not used on 32-bit arm */
-	bool sixty_four;
-};
-
-void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
-unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);
-
-int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
-int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
-		 phys_addr_t fault_ipa);
-
-#endif	/* __ARM_KVM_MMIO_H__ */
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 53ea7637b7b2..688c63412cc2 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -17,7 +17,6 @@
 #include <asm/esr.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_hyp.h>
-#include <asm/kvm_mmio.h>
 #include <asm/ptrace.h>
 #include <asm/cputype.h>
 #include <asm/virt.h>
@@ -341,7 +340,7 @@ static inline bool kvm_vcpu_dabt_is_cm(const struct kvm_vcpu *vcpu)
 	return !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_CM);
 }
 
-static inline int kvm_vcpu_dabt_get_as(const struct kvm_vcpu *vcpu)
+static inline unsigned int kvm_vcpu_dabt_get_as(const struct kvm_vcpu *vcpu)
 {
 	return 1 << ((kvm_vcpu_get_hsr(vcpu) & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT);
 }
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index c61260cf63c5..f6a77ddab956 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -24,7 +24,6 @@
 #include <asm/fpsimd.h>
 #include <asm/kvm.h>
 #include <asm/kvm_asm.h>
-#include <asm/kvm_mmio.h>
 #include <asm/thread_info.h>
 
 #define __KVM_HAVE_ARCH_INTC_INITIALIZED
@@ -325,9 +324,6 @@ struct kvm_vcpu_arch {
 	/* Don't run the guest (internal implementation need) */
 	bool pause;
 
-	/* IO related fields */
-	struct kvm_decode mmio_decode;
-
 	/* Cache some mmu pages needed inside spinlock regions */
 	struct kvm_mmu_memory_cache mmu_page_cache;
 
@@ -491,6 +487,14 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run,
 		       int exception_index);
 
+/* MMIO helpers */
+void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
+unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);
+
+int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
+		 phys_addr_t fault_ipa);
+
 int kvm_perf_init(void);
 int kvm_perf_teardown(void);
 
diff --git a/arch/arm64/include/asm/kvm_mmio.h b/arch/arm64/include/asm/kvm_mmio.h
deleted file mode 100644
index b204501a0c39..000000000000
--- a/arch/arm64/include/asm/kvm_mmio.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2012 - Virtual Open Systems and Columbia University
- * Author: Christoffer Dall <c.dall@virtualopensystems.com>
- */
-
-#ifndef __ARM64_KVM_MMIO_H__
-#define __ARM64_KVM_MMIO_H__
-
-#include <linux/kvm_host.h>
-#include <asm/kvm_arm.h>
-
-struct kvm_decode {
-	unsigned long rt;
-	bool sign_extend;
-	/* Witdth of the register accessed by the faulting instruction is 64-bits */
-	bool sixty_four;
-};
-
-void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
-unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);
-
-int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
-int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
-		 phys_addr_t fault_ipa);
-
-#endif	/* __ARM64_KVM_MMIO_H__ */