From: Rusty Russell <rusty at rustcorp.com.au>
If we do this the C-correct way, we use fewer casts and it's a bit clearer.
Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
---
arch/arm/include/asm/kvm_host.h | 6 +++-
arch/arm/kvm/emulate.c | 60 ++++++++++++++++++++-------------------
2 files changed, 36 insertions(+), 30 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 8002903..e211d8e 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -86,7 +86,11 @@ enum cp15_regs {
};
struct kvm_vcpu_arch {
- struct kvm_vcpu_regs regs;
+ /* We sometimes access these as an array for simplicity. */
+ union {
+ struct kvm_vcpu_regs regs;
+ u32 reg_array[sizeof(struct kvm_vcpu_regs) / sizeof(u32)];
+ };
/* System control coprocessor (cp15) */
u32 cp15[nr_cp15_regs];
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index 4f5f2de..108db38 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c
@@ -22,8 +22,10 @@
#include "trace.h"
-#define USR_REG_OFFSET(_reg) \
- offsetof(struct kvm_vcpu_arch, regs.usr_regs[_reg])
+#define REG_OFFSET(_reg) \
+ (offsetof(struct kvm_vcpu_regs, _reg) / sizeof(u32))
+
+#define USR_REG_OFFSET(_num) REG_OFFSET(usr_regs[_num])
static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
/* FIQ Registers */
@@ -31,14 +33,14 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
USR_REG_OFFSET(6), USR_REG_OFFSET(7),
- offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r8 */
- offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r9 */
- offsetof(struct kvm_vcpu_arch, regs.fiq_regs[2]), /* r10 */
- offsetof(struct kvm_vcpu_arch, regs.fiq_regs[3]), /* r11 */
- offsetof(struct kvm_vcpu_arch, regs.fiq_regs[4]), /* r12 */
- offsetof(struct kvm_vcpu_arch, regs.fiq_regs[5]), /* r13 */
- offsetof(struct kvm_vcpu_arch, regs.fiq_regs[6]), /* r14 */
- offsetof(struct kvm_vcpu_arch, regs.pc) /* r15 */
+ REG_OFFSET(fiq_regs[1]), /* r8 */
+ REG_OFFSET(fiq_regs[1]), /* r9 */
+ REG_OFFSET(fiq_regs[2]), /* r10 */
+ REG_OFFSET(fiq_regs[3]), /* r11 */
+ REG_OFFSET(fiq_regs[4]), /* r12 */
+ REG_OFFSET(fiq_regs[5]), /* r13 */
+ REG_OFFSET(fiq_regs[6]), /* r14 */
+ REG_OFFSET(pc) /* r15 */
},
/* IRQ Registers */
@@ -48,9 +50,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
- offsetof(struct kvm_vcpu_arch, regs.irq_regs[0]), /* r13 */
- offsetof(struct kvm_vcpu_arch, regs.irq_regs[1]), /* r14 */
- offsetof(struct kvm_vcpu_arch, regs.pc) /* r15 */
+ REG_OFFSET(irq_regs[0]), /* r13 */
+ REG_OFFSET(irq_regs[1]), /* r14 */
+ REG_OFFSET(pc) /* r15 */
},
/* SVC Registers */
@@ -60,9 +62,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
- offsetof(struct kvm_vcpu_arch, regs.svc_regs[0]), /* r13 */
- offsetof(struct kvm_vcpu_arch, regs.svc_regs[1]), /* r14 */
- offsetof(struct kvm_vcpu_arch, regs.pc) /* r15 */
+ REG_OFFSET(svc_regs[0]), /* r13 */
+ REG_OFFSET(svc_regs[1]), /* r14 */
+ REG_OFFSET(pc) /* r15 */
},
/* ABT Registers */
@@ -72,9 +74,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
- offsetof(struct kvm_vcpu_arch, regs.abt_regs[0]), /* r13 */
- offsetof(struct kvm_vcpu_arch, regs.abt_regs[1]), /* r14 */
- offsetof(struct kvm_vcpu_arch, regs.pc) /* r15 */
+ REG_OFFSET(abt_regs[0]), /* r13 */
+ REG_OFFSET(abt_regs[1]), /* r14 */
+ REG_OFFSET(pc) /* r15 */
},
/* UND Registers */
@@ -84,9 +86,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
- offsetof(struct kvm_vcpu_arch, regs.und_regs[0]), /* r13 */
- offsetof(struct kvm_vcpu_arch, regs.und_regs[1]), /* r14 */
- offsetof(struct kvm_vcpu_arch, regs.pc) /* r15 */
+ REG_OFFSET(und_regs[0]), /* r13 */
+ REG_OFFSET(und_regs[1]), /* r14 */
+ REG_OFFSET(pc) /* r15 */
},
/* USR Registers */
@@ -96,9 +98,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
- offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
- offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
- offsetof(struct kvm_vcpu_arch, regs.pc) /* r15 */
+ REG_OFFSET(usr_regs[13]), /* r13 */
+ REG_OFFSET(usr_regs[14]), /* r14 */
+ REG_OFFSET(pc) /* r15 */
},
/* SYS Registers */
@@ -108,9 +110,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
- offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
- offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
- offsetof(struct kvm_vcpu_arch, regs.pc) /* r15 */
+ REG_OFFSET(usr_regs[13]), /* r13 */
+ REG_OFFSET(usr_regs[14]), /* r14 */
+ REG_OFFSET(pc) /* r15 */
},
};
@@ -123,7 +125,7 @@ u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
BUG_ON(reg_num > 15);
BUG_ON(mode > MODE_SYS);
- return (u32 *)((void *)&vcpu->arch + vcpu_reg_offsets[mode][reg_num]);
+ return &vcpu->arch.reg_array[vcpu_reg_offsets[mode][reg_num]];
}
/******************************************************************************
