Instead of populating the the entire register file, read in registers as they are accessed, and write back only the modified ones. This saves a VMREAD and VMWRITE on Intel (for rsp, since it is not usually used during emulation), and a two 128-byte copies for the registers.
Signed-off-by: Avi Kivity <[email protected]> --- v3: fix misplaced parentheses in em_loop() and em_jcxz(), unbreaking those instructions. v2: add APIs for managing the register cache. This reduces the potential for confusion between ctxt->regs_dirty and vcpu->arch.regs_dirty. move cache management to the entry points add missing writebacks to int and task switch emulation arch/x86/include/asm/kvm_emulate.h | 20 ++- arch/x86/kvm/emulate.c | 305 ++++++++++++++++++++++--------------- arch/x86/kvm/x86.c | 45 +++--- 3 files changed, 223 insertions(+), 147 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index c764f43..282aee5 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -86,6 +86,19 @@ struct x86_instruction_info { struct x86_emulate_ops { /* + * read_gpr: read a general purpose register (rax - r15) + * + * @reg: gpr number. + */ + ulong (*read_gpr)(struct x86_emulate_ctxt *ctxt, unsigned reg); + /* + * write_gpr: write a general purpose register (rax - r15) + * + * @reg: gpr number. + * @val: value to write. + */ + void (*write_gpr)(struct x86_emulate_ctxt *ctxt, unsigned reg, ulong val); + /* * read_std: Read bytes of standard (non-emulated/special) memory. * Used for descriptor reading. * @addr: [IN ] Linear address from which to read. @@ -281,8 +294,10 @@ struct x86_emulate_ctxt { bool rip_relative; 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]; + unsigned long _regs[NR_VCPU_REGS]; struct operand *memopp; struct fetch_cache fetch; struct read_cache io_read; @@ -394,4 +409,7 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt, u16 tss_selector, int idt_index, int reason, bool has_error_code, u32 error_code); int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq); +void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt); +void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt); + #endif /* _ASM_X86_KVM_X86_EMULATE_H */ diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 10f0136..c6a6f7f 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -202,6 +202,42 @@ struct gprefix { #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a #define EFLG_RESERVED_ONE_MASK 2 +static ulong reg_read(struct x86_emulate_ctxt *ctxt, unsigned nr) +{ + if (!(ctxt->regs_valid & (1 << nr))) { + ctxt->regs_valid |= 1 << nr; + ctxt->_regs[nr] = ctxt->ops->read_gpr(ctxt, nr); + } + return ctxt->_regs[nr]; +} + +static ulong *reg_write(struct x86_emulate_ctxt *ctxt, unsigned nr) +{ + ctxt->regs_valid |= 1 << nr; + ctxt->regs_dirty |= 1 << nr; + return &ctxt->_regs[nr]; +} + +static ulong *reg_rmw(struct x86_emulate_ctxt *ctxt, unsigned nr) +{ + reg_read(ctxt, nr); + return reg_write(ctxt, nr); +} + +static void writeback_registers(struct x86_emulate_ctxt *ctxt) +{ + unsigned reg; + + for_each_set_bit(reg, (ulong *)&ctxt->regs_dirty, 16) + ctxt->ops->write_gpr(ctxt, reg, ctxt->_regs[reg]); +} + +static void invalidate_registers(struct x86_emulate_ctxt *ctxt) +{ + ctxt->regs_dirty = 0; + ctxt->regs_valid = 0; +} + /* * Instruction emulation: * Most instructions are emulated directly via a fragment of inline assembly @@ -374,8 +410,8 @@ struct gprefix { #define __emulate_1op_rax_rdx(ctxt, _op, _suffix, _ex) \ do { \ unsigned long _tmp; \ - ulong *rax = &(ctxt)->regs[VCPU_REGS_RAX]; \ - ulong *rdx = &(ctxt)->regs[VCPU_REGS_RDX]; \ + ulong *rax = reg_rmw((ctxt), VCPU_REGS_RAX); \ + ulong *rdx = reg_rmw((ctxt), VCPU_REGS_RDX); \ \ __asm__ __volatile__ ( \ _PRE_EFLAGS("0", "5", "1") \ @@ -773,14 +809,15 @@ static int do_insn_fetch(struct x86_emulate_ctxt *ctxt, * pointer into the block that addresses the relevant register. * @highbyte_regs specifies whether to decode AH,CH,DH,BH. */ -static void *decode_register(u8 modrm_reg, unsigned long *regs, +static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg, int highbyte_regs) { void *p; - p = ®s[modrm_reg]; if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) - p = (unsigned char *)®s[modrm_reg & 3] + 1; + p = (unsigned char *)reg_rmw(ctxt, modrm_reg & 3) + 1; + else + p = reg_rmw(ctxt, modrm_reg); return p; } @@ -969,10 +1006,10 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt, op->type = OP_REG; if (ctxt->d & ByteOp) { - op->addr.reg = decode_register(reg, ctxt->regs, highbyte_regs); + op->addr.reg = decode_register(ctxt, reg, highbyte_regs); op->bytes = 1; } else { - op->addr.reg = decode_register(reg, ctxt->regs, 0); + op->addr.reg = decode_register(ctxt, reg, 0); op->bytes = ctxt->op_bytes; } fetch_register_operand(op); @@ -1007,8 +1044,7 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, if (ctxt->modrm_mod == 3) { op->type = OP_REG; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; - op->addr.reg = decode_register(ctxt->modrm_rm, - ctxt->regs, ctxt->d & ByteOp); + op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, ctxt->d & ByteOp); if (ctxt->d & Sse) { op->type = OP_XMM; op->bytes = 16; @@ -1029,10 +1065,10 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, op->type = OP_MEM; if (ctxt->ad_bytes == 2) { - unsigned bx = ctxt->regs[VCPU_REGS_RBX]; - unsigned bp = ctxt->regs[VCPU_REGS_RBP]; - unsigned si = ctxt->regs[VCPU_REGS_RSI]; - unsigned di = ctxt->regs[VCPU_REGS_RDI]; + unsigned bx = reg_read(ctxt, VCPU_REGS_RBX); + unsigned bp = reg_read(ctxt, VCPU_REGS_RBP); + unsigned si = reg_read(ctxt, VCPU_REGS_RSI); + unsigned di = reg_read(ctxt, VCPU_REGS_RDI); /* 16-bit ModR/M decode. */ switch (ctxt->modrm_mod) { @@ -1089,17 +1125,17 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0) modrm_ea += insn_fetch(s32, ctxt); else { - modrm_ea += ctxt->regs[base_reg]; + modrm_ea += reg_read(ctxt, base_reg); adjust_modrm_seg(ctxt, base_reg); } if (index_reg != 4) - modrm_ea += ctxt->regs[index_reg] << scale; + modrm_ea += reg_read(ctxt, index_reg) << scale; } else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) { if (ctxt->mode == X86EMUL_MODE_PROT64) ctxt->rip_relative = 1; } else { base_reg = ctxt->modrm_rm; - modrm_ea += ctxt->regs[base_reg]; + modrm_ea += reg_read(ctxt, base_reg); adjust_modrm_seg(ctxt, base_reg); } switch (ctxt->modrm_mod) { @@ -1237,10 +1273,10 @@ static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, if (rc->pos == rc->end) { /* refill pio read ahead */ unsigned int in_page, n; unsigned int count = ctxt->rep_prefix ? - address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) : 1; + address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) : 1; in_page = (ctxt->eflags & EFLG_DF) ? - offset_in_page(ctxt->regs[VCPU_REGS_RDI]) : - PAGE_SIZE - offset_in_page(ctxt->regs[VCPU_REGS_RDI]); + offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)) : + PAGE_SIZE - offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)); n = min(min(in_page, (unsigned int)sizeof(rc->data)) / size, count); if (n == 0) @@ -1519,8 +1555,8 @@ static int push(struct x86_emulate_ctxt *ctxt, void *data, int bytes) { struct segmented_address addr; - register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], -bytes); - addr.ea = register_address(ctxt, ctxt->regs[VCPU_REGS_RSP]); + register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RSP), -bytes); + addr.ea = register_address(ctxt, reg_read(ctxt, VCPU_REGS_RSP)); addr.seg = VCPU_SREG_SS; return segmented_write(ctxt, addr, data, bytes); @@ -1539,13 +1575,13 @@ static int emulate_pop(struct x86_emulate_ctxt *ctxt, int rc; struct segmented_address addr; - addr.ea = register_address(ctxt, ctxt->regs[VCPU_REGS_RSP]); + addr.ea = register_address(ctxt, reg_read(ctxt, VCPU_REGS_RSP)); addr.seg = VCPU_SREG_SS; rc = segmented_read(ctxt, addr, dest, len); if (rc != X86EMUL_CONTINUE) return rc; - register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], len); + register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RSP), len); return rc; } @@ -1607,26 +1643,28 @@ static int em_enter(struct x86_emulate_ctxt *ctxt) int rc; unsigned frame_size = ctxt->src.val; unsigned nesting_level = ctxt->src2.val & 31; + ulong rbp; if (nesting_level) return X86EMUL_UNHANDLEABLE; - rc = push(ctxt, &ctxt->regs[VCPU_REGS_RBP], stack_size(ctxt)); + rbp = reg_read(ctxt, VCPU_REGS_RBP); + rc = push(ctxt, &rbp, stack_size(ctxt)); if (rc != X86EMUL_CONTINUE) return rc; - assign_masked(&ctxt->regs[VCPU_REGS_RBP], ctxt->regs[VCPU_REGS_RSP], + assign_masked(reg_rmw(ctxt, VCPU_REGS_RBP), reg_read(ctxt, VCPU_REGS_RSP), stack_mask(ctxt)); - assign_masked(&ctxt->regs[VCPU_REGS_RSP], - ctxt->regs[VCPU_REGS_RSP] - frame_size, + assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), + reg_read(ctxt, VCPU_REGS_RSP) - frame_size, stack_mask(ctxt)); return X86EMUL_CONTINUE; } static int em_leave(struct x86_emulate_ctxt *ctxt) { - assign_masked(&ctxt->regs[VCPU_REGS_RSP], ctxt->regs[VCPU_REGS_RBP], + assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), reg_read(ctxt, VCPU_REGS_RBP), stack_mask(ctxt)); - return emulate_pop(ctxt, &ctxt->regs[VCPU_REGS_RBP], ctxt->op_bytes); + return emulate_pop(ctxt, reg_rmw(ctxt, VCPU_REGS_RBP), ctxt->op_bytes); } static int em_push_sreg(struct x86_emulate_ctxt *ctxt) @@ -1654,13 +1692,13 @@ static int em_pop_sreg(struct x86_emulate_ctxt *ctxt) static int em_pusha(struct x86_emulate_ctxt *ctxt) { - unsigned long old_esp = ctxt->regs[VCPU_REGS_RSP]; + unsigned long old_esp = reg_read(ctxt, VCPU_REGS_RSP); int rc = X86EMUL_CONTINUE; int reg = VCPU_REGS_RAX; while (reg <= VCPU_REGS_RDI) { (reg == VCPU_REGS_RSP) ? - (ctxt->src.val = old_esp) : (ctxt->src.val = ctxt->regs[reg]); + (ctxt->src.val = old_esp) : (ctxt->src.val = reg_read(ctxt, reg)); rc = em_push(ctxt); if (rc != X86EMUL_CONTINUE) @@ -1685,12 +1723,12 @@ static int em_popa(struct x86_emulate_ctxt *ctxt) while (reg >= VCPU_REGS_RAX) { if (reg == VCPU_REGS_RSP) { - register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], + register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RSP), ctxt->op_bytes); --reg; } - rc = emulate_pop(ctxt, &ctxt->regs[reg], ctxt->op_bytes); + rc = emulate_pop(ctxt, reg_rmw(ctxt, reg), ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) break; --reg; @@ -1698,7 +1736,7 @@ static int em_popa(struct x86_emulate_ctxt *ctxt) return rc; } -int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) +static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) { struct x86_emulate_ops *ops = ctxt->ops; int rc; @@ -1747,11 +1785,22 @@ int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) return rc; } +int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) +{ + int rc; + + invalidate_registers(ctxt); + rc = __emulate_int_real(ctxt, irq); + if (rc == X86EMUL_CONTINUE) + writeback_registers(ctxt); + return rc; +} + static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq) { switch(ctxt->mode) { case X86EMUL_MODE_REAL: - return emulate_int_real(ctxt, irq); + return __emulate_int_real(ctxt, irq); case X86EMUL_MODE_VM86: case X86EMUL_MODE_PROT16: case X86EMUL_MODE_PROT32: @@ -1958,14 +2007,14 @@ static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt) { u64 old = ctxt->dst.orig_val64; - if (((u32) (old >> 0) != (u32) ctxt->regs[VCPU_REGS_RAX]) || - ((u32) (old >> 32) != (u32) ctxt->regs[VCPU_REGS_RDX])) { - ctxt->regs[VCPU_REGS_RAX] = (u32) (old >> 0); - ctxt->regs[VCPU_REGS_RDX] = (u32) (old >> 32); + if (((u32) (old >> 0) != (u32) reg_read(ctxt, VCPU_REGS_RAX)) || + ((u32) (old >> 32) != (u32) reg_read(ctxt, VCPU_REGS_RDX))) { + *reg_write(ctxt, VCPU_REGS_RAX) = (u32) (old >> 0); + *reg_write(ctxt, VCPU_REGS_RDX) = (u32) (old >> 32); ctxt->eflags &= ~EFLG_ZF; } else { - ctxt->dst.val64 = ((u64)ctxt->regs[VCPU_REGS_RCX] << 32) | - (u32) ctxt->regs[VCPU_REGS_RBX]; + ctxt->dst.val64 = ((u64)reg_read(ctxt, VCPU_REGS_RCX) << 32) | + (u32) reg_read(ctxt, VCPU_REGS_RBX); ctxt->eflags |= EFLG_ZF; } @@ -2001,7 +2050,7 @@ static int em_cmpxchg(struct x86_emulate_ctxt *ctxt) { /* Save real source value, then compare EAX against destination. */ ctxt->src.orig_val = ctxt->src.val; - ctxt->src.val = ctxt->regs[VCPU_REGS_RAX]; + ctxt->src.val = reg_read(ctxt, VCPU_REGS_RAX); emulate_2op_SrcV(ctxt, "cmp"); if (ctxt->eflags & EFLG_ZF) { @@ -2010,7 +2059,7 @@ static int em_cmpxchg(struct x86_emulate_ctxt *ctxt) } else { /* Failure: write the value we saw to EAX. */ ctxt->dst.type = OP_REG; - ctxt->dst.addr.reg = (unsigned long *)&ctxt->regs[VCPU_REGS_RAX]; + ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); } return X86EMUL_CONTINUE; } @@ -2147,10 +2196,10 @@ static int em_syscall(struct x86_emulate_ctxt *ctxt) ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); - ctxt->regs[VCPU_REGS_RCX] = ctxt->_eip; + *reg_write(ctxt, VCPU_REGS_RCX) = ctxt->_eip; if (efer & EFER_LMA) { #ifdef CONFIG_X86_64 - ctxt->regs[VCPU_REGS_R11] = ctxt->eflags & ~EFLG_RF; + *reg_write(ctxt, VCPU_REGS_R11) = ctxt->eflags & ~EFLG_RF; ops->get_msr(ctxt, ctxt->mode == X86EMUL_MODE_PROT64 ? @@ -2229,7 +2278,7 @@ static int em_sysenter(struct x86_emulate_ctxt *ctxt) ctxt->_eip = msr_data; ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data); - ctxt->regs[VCPU_REGS_RSP] = msr_data; + *reg_write(ctxt, VCPU_REGS_RSP) = msr_data; return X86EMUL_CONTINUE; } @@ -2279,8 +2328,8 @@ static int em_sysexit(struct x86_emulate_ctxt *ctxt) ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); - ctxt->_eip = ctxt->regs[VCPU_REGS_RDX]; - ctxt->regs[VCPU_REGS_RSP] = ctxt->regs[VCPU_REGS_RCX]; + ctxt->_eip = reg_read(ctxt, VCPU_REGS_RDX); + *reg_write(ctxt, VCPU_REGS_RSP) = reg_read(ctxt, VCPU_REGS_RCX); return X86EMUL_CONTINUE; } @@ -2349,14 +2398,14 @@ static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, { tss->ip = ctxt->_eip; tss->flag = ctxt->eflags; - tss->ax = ctxt->regs[VCPU_REGS_RAX]; - tss->cx = ctxt->regs[VCPU_REGS_RCX]; - tss->dx = ctxt->regs[VCPU_REGS_RDX]; - tss->bx = ctxt->regs[VCPU_REGS_RBX]; - tss->sp = ctxt->regs[VCPU_REGS_RSP]; - tss->bp = ctxt->regs[VCPU_REGS_RBP]; - tss->si = ctxt->regs[VCPU_REGS_RSI]; - tss->di = ctxt->regs[VCPU_REGS_RDI]; + tss->ax = reg_read(ctxt, VCPU_REGS_RAX); + tss->cx = reg_read(ctxt, VCPU_REGS_RCX); + tss->dx = reg_read(ctxt, VCPU_REGS_RDX); + tss->bx = reg_read(ctxt, VCPU_REGS_RBX); + tss->sp = reg_read(ctxt, VCPU_REGS_RSP); + tss->bp = reg_read(ctxt, VCPU_REGS_RBP); + tss->si = reg_read(ctxt, VCPU_REGS_RSI); + tss->di = reg_read(ctxt, VCPU_REGS_RDI); tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); @@ -2372,14 +2421,14 @@ static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, ctxt->_eip = tss->ip; ctxt->eflags = tss->flag | 2; - ctxt->regs[VCPU_REGS_RAX] = tss->ax; - ctxt->regs[VCPU_REGS_RCX] = tss->cx; - ctxt->regs[VCPU_REGS_RDX] = tss->dx; - ctxt->regs[VCPU_REGS_RBX] = tss->bx; - ctxt->regs[VCPU_REGS_RSP] = tss->sp; - ctxt->regs[VCPU_REGS_RBP] = tss->bp; - ctxt->regs[VCPU_REGS_RSI] = tss->si; - ctxt->regs[VCPU_REGS_RDI] = tss->di; + *reg_write(ctxt, VCPU_REGS_RAX) = tss->ax; + *reg_write(ctxt, VCPU_REGS_RCX) = tss->cx; + *reg_write(ctxt, VCPU_REGS_RDX) = tss->dx; + *reg_write(ctxt, VCPU_REGS_RBX) = tss->bx; + *reg_write(ctxt, VCPU_REGS_RSP) = tss->sp; + *reg_write(ctxt, VCPU_REGS_RBP) = tss->bp; + *reg_write(ctxt, VCPU_REGS_RSI) = tss->si; + *reg_write(ctxt, VCPU_REGS_RDI) = tss->di; /* * SDM says that segment selectors are loaded before segment @@ -2464,14 +2513,14 @@ static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, tss->cr3 = ctxt->ops->get_cr(ctxt, 3); tss->eip = ctxt->_eip; tss->eflags = ctxt->eflags; - tss->eax = ctxt->regs[VCPU_REGS_RAX]; - tss->ecx = ctxt->regs[VCPU_REGS_RCX]; - tss->edx = ctxt->regs[VCPU_REGS_RDX]; - tss->ebx = ctxt->regs[VCPU_REGS_RBX]; - tss->esp = ctxt->regs[VCPU_REGS_RSP]; - tss->ebp = ctxt->regs[VCPU_REGS_RBP]; - tss->esi = ctxt->regs[VCPU_REGS_RSI]; - tss->edi = ctxt->regs[VCPU_REGS_RDI]; + tss->eax = reg_read(ctxt, VCPU_REGS_RAX); + tss->ecx = reg_read(ctxt, VCPU_REGS_RCX); + tss->edx = reg_read(ctxt, VCPU_REGS_RDX); + tss->ebx = reg_read(ctxt, VCPU_REGS_RBX); + tss->esp = reg_read(ctxt, VCPU_REGS_RSP); + tss->ebp = reg_read(ctxt, VCPU_REGS_RBP); + tss->esi = reg_read(ctxt, VCPU_REGS_RSI); + tss->edi = reg_read(ctxt, VCPU_REGS_RDI); tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); @@ -2493,14 +2542,14 @@ static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, ctxt->eflags = tss->eflags | 2; /* General purpose registers */ - ctxt->regs[VCPU_REGS_RAX] = tss->eax; - ctxt->regs[VCPU_REGS_RCX] = tss->ecx; - ctxt->regs[VCPU_REGS_RDX] = tss->edx; - ctxt->regs[VCPU_REGS_RBX] = tss->ebx; - ctxt->regs[VCPU_REGS_RSP] = tss->esp; - ctxt->regs[VCPU_REGS_RBP] = tss->ebp; - ctxt->regs[VCPU_REGS_RSI] = tss->esi; - ctxt->regs[VCPU_REGS_RDI] = tss->edi; + *reg_write(ctxt, VCPU_REGS_RAX) = tss->eax; + *reg_write(ctxt, VCPU_REGS_RCX) = tss->ecx; + *reg_write(ctxt, VCPU_REGS_RDX) = tss->edx; + *reg_write(ctxt, VCPU_REGS_RBX) = tss->ebx; + *reg_write(ctxt, VCPU_REGS_RSP) = tss->esp; + *reg_write(ctxt, VCPU_REGS_RBP) = tss->ebp; + *reg_write(ctxt, VCPU_REGS_RSI) = tss->esi; + *reg_write(ctxt, VCPU_REGS_RDI) = tss->edi; /* * SDM says that segment selectors are loaded before segment @@ -2715,14 +2764,17 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt, { int rc; + invalidate_registers(ctxt); ctxt->_eip = ctxt->eip; ctxt->dst.type = OP_NONE; rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason, has_error_code, error_code); - if (rc == X86EMUL_CONTINUE) + if (rc == X86EMUL_CONTINUE) { ctxt->eip = ctxt->_eip; + writeback_registers(ctxt); + } return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; } @@ -2732,8 +2784,8 @@ static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned seg, { int df = (ctxt->eflags & EFLG_DF) ? -1 : 1; - register_address_increment(ctxt, &ctxt->regs[reg], df * op->bytes); - op->addr.mem.ea = register_address(ctxt, ctxt->regs[reg]); + register_address_increment(ctxt, reg_rmw(ctxt, reg), df * op->bytes); + op->addr.mem.ea = register_address(ctxt, reg_read(ctxt, reg)); op->addr.mem.seg = seg; } @@ -2819,7 +2871,7 @@ static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt) rc = emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; - register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], ctxt->src.val); + register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RSP), ctxt->src.val); return X86EMUL_CONTINUE; } @@ -2909,7 +2961,7 @@ static int em_cwd(struct x86_emulate_ctxt *ctxt) { ctxt->dst.type = OP_REG; ctxt->dst.bytes = ctxt->src.bytes; - ctxt->dst.addr.reg = &ctxt->regs[VCPU_REGS_RDX]; + ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1); return X86EMUL_CONTINUE; @@ -2920,8 +2972,8 @@ static int em_rdtsc(struct x86_emulate_ctxt *ctxt) u64 tsc = 0; ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc); - ctxt->regs[VCPU_REGS_RAX] = (u32)tsc; - ctxt->regs[VCPU_REGS_RDX] = tsc >> 32; + *reg_write(ctxt, VCPU_REGS_RAX) = (u32)tsc; + *reg_write(ctxt, VCPU_REGS_RDX) = tsc >> 32; return X86EMUL_CONTINUE; } @@ -2929,10 +2981,10 @@ static int em_rdpmc(struct x86_emulate_ctxt *ctxt) { u64 pmc; - if (ctxt->ops->read_pmc(ctxt, ctxt->regs[VCPU_REGS_RCX], &pmc)) + if (ctxt->ops->read_pmc(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &pmc)) return emulate_gp(ctxt, 0); - ctxt->regs[VCPU_REGS_RAX] = (u32)pmc; - ctxt->regs[VCPU_REGS_RDX] = pmc >> 32; + *reg_write(ctxt, VCPU_REGS_RAX) = (u32)pmc; + *reg_write(ctxt, VCPU_REGS_RDX) = pmc >> 32; return X86EMUL_CONTINUE; } @@ -2974,9 +3026,9 @@ static int em_wrmsr(struct x86_emulate_ctxt *ctxt) { u64 msr_data; - msr_data = (u32)ctxt->regs[VCPU_REGS_RAX] - | ((u64)ctxt->regs[VCPU_REGS_RDX] << 32); - if (ctxt->ops->set_msr(ctxt, ctxt->regs[VCPU_REGS_RCX], msr_data)) + msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX) + | ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32); + if (ctxt->ops->set_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), msr_data)) return emulate_gp(ctxt, 0); return X86EMUL_CONTINUE; @@ -2986,11 +3038,11 @@ static int em_rdmsr(struct x86_emulate_ctxt *ctxt) { u64 msr_data; - if (ctxt->ops->get_msr(ctxt, ctxt->regs[VCPU_REGS_RCX], &msr_data)) + if (ctxt->ops->get_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &msr_data)) return emulate_gp(ctxt, 0); - ctxt->regs[VCPU_REGS_RAX] = (u32)msr_data; - ctxt->regs[VCPU_REGS_RDX] = msr_data >> 32; + *reg_write(ctxt, VCPU_REGS_RAX) = (u32)msr_data; + *reg_write(ctxt, VCPU_REGS_RDX) = msr_data >> 32; return X86EMUL_CONTINUE; } @@ -3170,8 +3222,8 @@ static int em_lmsw(struct x86_emulate_ctxt *ctxt) static int em_loop(struct x86_emulate_ctxt *ctxt) { - register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX], -1); - if ((address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) != 0) && + register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RCX), -1); + if ((address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) != 0) && (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags))) jmp_rel(ctxt, ctxt->src.val); @@ -3180,7 +3232,7 @@ static int em_loop(struct x86_emulate_ctxt *ctxt) static int em_jcxz(struct x86_emulate_ctxt *ctxt) { - if (address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) == 0) + if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) jmp_rel(ctxt, ctxt->src.val); return X86EMUL_CONTINUE; @@ -3268,20 +3320,20 @@ static int em_cpuid(struct x86_emulate_ctxt *ctxt) { u32 eax, ebx, ecx, edx; - eax = ctxt->regs[VCPU_REGS_RAX]; - ecx = ctxt->regs[VCPU_REGS_RCX]; + eax = reg_read(ctxt, VCPU_REGS_RAX); + ecx = reg_read(ctxt, VCPU_REGS_RCX); ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx); - ctxt->regs[VCPU_REGS_RAX] = eax; - ctxt->regs[VCPU_REGS_RBX] = ebx; - ctxt->regs[VCPU_REGS_RCX] = ecx; - ctxt->regs[VCPU_REGS_RDX] = edx; + *reg_write(ctxt, VCPU_REGS_RAX) = eax; + *reg_write(ctxt, VCPU_REGS_RBX) = ebx; + *reg_write(ctxt, VCPU_REGS_RCX) = ecx; + *reg_write(ctxt, VCPU_REGS_RDX) = edx; return X86EMUL_CONTINUE; } static int em_lahf(struct x86_emulate_ctxt *ctxt) { - ctxt->regs[VCPU_REGS_RAX] &= ~0xff00UL; - ctxt->regs[VCPU_REGS_RAX] |= (ctxt->eflags & 0xff) << 8; + *reg_rmw(ctxt, VCPU_REGS_RAX) &= ~0xff00UL; + *reg_rmw(ctxt, VCPU_REGS_RAX) |= (ctxt->eflags & 0xff) << 8; return X86EMUL_CONTINUE; } @@ -3438,7 +3490,7 @@ static int check_svme(struct x86_emulate_ctxt *ctxt) static int check_svme_pa(struct x86_emulate_ctxt *ctxt) { - u64 rax = ctxt->regs[VCPU_REGS_RAX]; + u64 rax = reg_read(ctxt, VCPU_REGS_RAX); /* Valid physical address? */ if (rax & 0xffff000000000000ULL) @@ -3460,7 +3512,7 @@ static int check_rdtsc(struct x86_emulate_ctxt *ctxt) static int check_rdpmc(struct x86_emulate_ctxt *ctxt) { u64 cr4 = ctxt->ops->get_cr(ctxt, 4); - u64 rcx = ctxt->regs[VCPU_REGS_RCX]; + u64 rcx = reg_read(ctxt, VCPU_REGS_RCX); if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) || (rcx > 3)) @@ -3918,7 +3970,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, case OpAcc: op->type = OP_REG; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; - op->addr.reg = &ctxt->regs[VCPU_REGS_RAX]; + op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); fetch_register_operand(op); op->orig_val = op->val; break; @@ -3926,19 +3978,19 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, op->type = OP_MEM; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; op->addr.mem.ea = - register_address(ctxt, ctxt->regs[VCPU_REGS_RDI]); + register_address(ctxt, reg_read(ctxt, VCPU_REGS_RDI)); op->addr.mem.seg = VCPU_SREG_ES; op->val = 0; break; case OpDX: op->type = OP_REG; op->bytes = 2; - op->addr.reg = &ctxt->regs[VCPU_REGS_RDX]; + op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); fetch_register_operand(op); break; case OpCL: op->bytes = 1; - op->val = ctxt->regs[VCPU_REGS_RCX] & 0xff; + op->val = reg_read(ctxt, VCPU_REGS_RCX) & 0xff; break; case OpImmByte: rc = decode_imm(ctxt, op, 1, true); @@ -3969,7 +4021,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, op->type = OP_MEM; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; op->addr.mem.ea = - register_address(ctxt, ctxt->regs[VCPU_REGS_RSI]); + register_address(ctxt, reg_read(ctxt, VCPU_REGS_RSI)); op->addr.mem.seg = seg_override(ctxt); op->val = 0; break; @@ -4275,6 +4327,7 @@ static void fetch_possible_mmx_operand(struct x86_emulate_ctxt *ctxt, read_mmx_reg(ctxt, &op->mm_val, op->addr.mm); } + int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) { struct x86_emulate_ops *ops = ctxt->ops; @@ -4359,7 +4412,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) if (ctxt->rep_prefix && (ctxt->d & String)) { /* All REP prefixes have the same first termination condition */ - if (address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) == 0) { + if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) { ctxt->eip = ctxt->_eip; goto done; } @@ -4432,7 +4485,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) ctxt->dst.val = ctxt->src.addr.mem.ea; break; case 0x90 ... 0x97: /* nop / xchg reg, rax */ - if (ctxt->dst.addr.reg == &ctxt->regs[VCPU_REGS_RAX]) + if (ctxt->dst.addr.reg == reg_rmw(ctxt, VCPU_REGS_RAX)) break; rc = em_xchg(ctxt); break; @@ -4460,7 +4513,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) rc = em_grp2(ctxt); break; case 0xd2 ... 0xd3: /* Grp2 */ - ctxt->src.val = ctxt->regs[VCPU_REGS_RCX]; + ctxt->src.val = reg_read(ctxt, VCPU_REGS_RCX); rc = em_grp2(ctxt); break; case 0xe9: /* jmp rel */ @@ -4515,14 +4568,14 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) if (ctxt->rep_prefix && (ctxt->d & String)) { struct read_cache *r = &ctxt->io_read; - register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX], -1); + register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RCX), -1); if (!string_insn_completed(ctxt)) { /* * Re-enter guest when pio read ahead buffer is empty * or, if it is not used, after each 1024 iteration. */ - if ((r->end != 0 || ctxt->regs[VCPU_REGS_RCX] & 0x3ff) && + if ((r->end != 0 || reg_read(ctxt, VCPU_REGS_RCX) & 0x3ff) && (r->end == 0 || r->end != r->pos)) { /* * Reset read cache. Usually happens before @@ -4530,6 +4583,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) * we have to do it here. */ ctxt->mem_read.end = 0; + writeback_registers(ctxt); return EMULATION_RESTART; } goto done; /* skip rip writeback */ @@ -4544,6 +4598,9 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) if (rc == X86EMUL_INTERCEPTED) return EMULATION_INTERCEPTED; + if (rc == X86EMUL_CONTINUE) + writeback_registers(ctxt); + return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; twobyte_insn: @@ -4616,3 +4673,13 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) cannot_emulate: return EMULATION_FAILED; } + +void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt) +{ + invalidate_registers(ctxt); +} + +void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt) +{ + writeback_registers(ctxt); +} diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 91a5958..d5ebe7e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4305,7 +4305,19 @@ static void emulator_get_cpuid(struct x86_emulate_ctxt *ctxt, kvm_cpuid(emul_to_vcpu(ctxt), eax, ebx, ecx, edx); } +static ulong emulator_read_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg) +{ + return kvm_register_read(emul_to_vcpu(ctxt), reg); +} + +static void emulator_write_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg, ulong val) +{ + kvm_register_write(emul_to_vcpu(ctxt), reg, val); +} + static struct x86_emulate_ops emulate_ops = { + .read_gpr = emulator_read_gpr, + .write_gpr = emulator_write_gpr, .read_std = kvm_read_guest_virt_system, .write_std = kvm_write_guest_virt_system, .fetch = kvm_fetch_guest_virt, @@ -4340,14 +4352,6 @@ static void emulator_get_cpuid(struct x86_emulate_ctxt *ctxt, .get_cpuid = emulator_get_cpuid, }; -static void cache_all_regs(struct kvm_vcpu *vcpu) -{ - kvm_register_read(vcpu, VCPU_REGS_RAX); - kvm_register_read(vcpu, VCPU_REGS_RSP); - kvm_register_read(vcpu, VCPU_REGS_RIP); - vcpu->arch.regs_dirty = ~0; -} - static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask) { u32 int_shadow = kvm_x86_ops->get_interrupt_shadow(vcpu, mask); @@ -4374,12 +4378,10 @@ static void inject_emulated_exception(struct kvm_vcpu *vcpu) kvm_queue_exception(vcpu, ctxt->exception.vector); } -static void init_decode_cache(struct x86_emulate_ctxt *ctxt, - const unsigned long *regs) +static void init_decode_cache(struct x86_emulate_ctxt *ctxt) { memset(&ctxt->twobyte, 0, - (void *)&ctxt->regs - (void *)&ctxt->twobyte); - memcpy(ctxt->regs, regs, sizeof(ctxt->regs)); + (void *)&ctxt->_regs - (void *)&ctxt->twobyte); ctxt->fetch.start = 0; ctxt->fetch.end = 0; @@ -4394,14 +4396,6 @@ static void init_emulate_ctxt(struct kvm_vcpu *vcpu) struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt; int cs_db, cs_l; - /* - * TODO: fix emulate.c to use guest_read/write_register - * instead of direct ->regs accesses, can save hundred cycles - * on Intel for instructions that don't read/change RSP, for - * for example. - */ - cache_all_regs(vcpu); - kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l); ctxt->eflags = kvm_get_rflags(vcpu); @@ -4413,7 +4407,7 @@ static void init_emulate_ctxt(struct kvm_vcpu *vcpu) X86EMUL_MODE_PROT16; ctxt->guest_mode = is_guest_mode(vcpu); - init_decode_cache(ctxt, vcpu->arch.regs); + init_decode_cache(ctxt); vcpu->arch.emulate_regs_need_sync_from_vcpu = false; } @@ -4433,7 +4427,6 @@ int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip) return EMULATE_FAIL; ctxt->eip = ctxt->_eip; - memcpy(vcpu->arch.regs, ctxt->regs, sizeof ctxt->regs); kvm_rip_write(vcpu, ctxt->eip); kvm_set_rflags(vcpu, ctxt->eflags); @@ -4581,7 +4574,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, changes registers values during IO operation */ if (vcpu->arch.emulate_regs_need_sync_from_vcpu) { vcpu->arch.emulate_regs_need_sync_from_vcpu = false; - memcpy(ctxt->regs, vcpu->arch.regs, sizeof ctxt->regs); + emulator_invalidate_register_cache(ctxt); } restart: @@ -4619,7 +4612,6 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, toggle_interruptibility(vcpu, ctxt->interruptibility); kvm_set_rflags(vcpu, ctxt->eflags); kvm_make_request(KVM_REQ_EVENT, vcpu); - memcpy(vcpu->arch.regs, ctxt->regs, sizeof ctxt->regs); vcpu->arch.emulate_regs_need_sync_to_vcpu = false; kvm_rip_write(vcpu, ctxt->eip); } else @@ -5573,8 +5565,7 @@ int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) * that usually, but some bad designed PV devices (vmware * backdoor interface) need this to work */ - struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt; - memcpy(vcpu->arch.regs, ctxt->regs, sizeof ctxt->regs); + emulator_writeback_register_cache(&vcpu->arch.emulate_ctxt); vcpu->arch.emulate_regs_need_sync_to_vcpu = false; } regs->rax = kvm_register_read(vcpu, VCPU_REGS_RAX); @@ -5705,6 +5696,7 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index, { struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt; int ret; + unsigned reg; init_emulate_ctxt(vcpu); @@ -5714,7 +5706,6 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index, if (ret) return EMULATE_FAIL; - memcpy(vcpu->arch.regs, ctxt->regs, sizeof ctxt->regs); kvm_rip_write(vcpu, ctxt->eip); kvm_set_rflags(vcpu, ctxt->eflags); kvm_make_request(KVM_REQ_EVENT, vcpu); -- 1.7.11.3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
