[PATCH 2/8] ARM: KVM: neaten offset calculations.
From: Rusty Russell <hidden>
Date: 2012-03-09 04:42:07
Also in:
lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
From: Rusty Russell <redacted> If we do this the C-correct way, we use fewer casts and it's a bit clearer. Signed-off-by: Rusty Russell <redacted> --- 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]]; } /******************************************************************************