Commit c44b4c6a authored by Bandan Das's avatar Bandan Das Committed by Paolo Bonzini
Browse files

KVM: emulate: clean up initializations in init_decode_cache 



A lot of initializations are unnecessary as they get set to
appropriate values before actually being used. Optimize
placement of fields in x86_emulate_ctxt

Signed-off-by: default avatarBandan Das <bsd@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 02357bdc

arch/x86/include/asm/kvm_emulate.h

+11 −9
Original line number Diff line number Diff line
@@ -288,30 +288,32 @@ struct x86_emulate_ctxt { 
	u8 opcode_len;

	u8 b;

	u8 intercept;

	u8 lock_prefix;

	u8 rep_prefix;

	u8 op_bytes;

	u8 ad_bytes;

	u8 rex_prefix;

	struct operand src;

	struct operand src2;

	struct operand dst;

	bool has_seg_override;

	u8 seg_override;

	u64 d;

	int (*execute)(struct x86_emulate_ctxt *ctxt);

	int (*check_perm)(struct x86_emulate_ctxt *ctxt);

	bool has_seg_override;

	bool rip_relative;

	u8 rex_prefix;

	u8 lock_prefix;

	u8 rep_prefix;

	u8 seg_override;

	/* bitmaps of registers in _regs[] that can be read */

	u32 regs_valid;

	/* bitmaps of registers in _regs[] that have been written */

	u32 regs_dirty;

	/* modrm */

	u8 modrm;

	u8 modrm_mod;

	u8 modrm_reg;

	u8 modrm_rm;

	u8 modrm_seg;

	bool rip_relative;

	u64 d;

	unsigned long _eip;

	struct operand memop;

	u32 regs_valid;  /* bitmaps of registers in _regs[] that can be read */

	u32 regs_dirty;  /* bitmaps of registers in _regs[] that have been written */

	/* Fields above regs are cleared together. */

	unsigned long _regs[NR_VCPU_REGS];

	struct operand *memopp;

arch/x86/kvm/emulate.c

+2 −5
Original line number Diff line number Diff line
@@ -4534,14 +4534,11 @@ static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *)) 


void init_decode_cache(struct x86_emulate_ctxt *ctxt)

{

	memset(&ctxt->opcode_len, 0,

	       (void *)&ctxt->_regs - (void *)&ctxt->opcode_len);

	memset(&ctxt->has_seg_override, 0,

	       (void *)&ctxt->modrm - (void *)&ctxt->has_seg_override);



	ctxt->fetch.start = 0;

	ctxt->fetch.end = 0;

	ctxt->io_read.pos = 0;

	ctxt->io_read.end = 0;

	ctxt->mem_read.pos = 0;

	ctxt->mem_read.end = 0;

}