Commit 4c690a1e authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: Allow passing 64-bit values to the emulated read/write API 



This simplifies the API somewhat (by eliminating the special-case
cmpxchg8b on i386).

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 1165f5fe

drivers/kvm/kvm_main.c

+9 −36
Original line number Diff line number Diff line
@@ -970,7 +970,7 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn) 
}



static int emulator_read_std(unsigned long addr,

			     unsigned long *val,

			     void *val,

			     unsigned int bytes,

			     struct x86_emulate_ctxt *ctxt)

{
@@ -1006,7 +1006,7 @@ static int emulator_read_std(unsigned long addr, 
}



static int emulator_write_std(unsigned long addr,

			      unsigned long val,

			      const void *val,

			      unsigned int bytes,

			      struct x86_emulate_ctxt *ctxt)

{
@@ -1016,7 +1016,7 @@ static int emulator_write_std(unsigned long addr, 
}



static int emulator_read_emulated(unsigned long addr,

				  unsigned long *val,

				  void *val,

				  unsigned int bytes,

				  struct x86_emulate_ctxt *ctxt)

{
@@ -1044,7 +1044,7 @@ static int emulator_read_emulated(unsigned long addr, 
}



static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,

			       unsigned long val, int bytes)

			       const void *val, int bytes)

{

	struct page *page;

	void *virt;
@@ -1057,14 +1057,14 @@ static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, 
	kvm_mmu_pre_write(vcpu, gpa, bytes);

	mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT);

	virt = kmap_atomic(page, KM_USER0);

	memcpy(virt + offset_in_page(gpa), &val, bytes);

	memcpy(virt + offset_in_page(gpa), val, bytes);

	kunmap_atomic(virt, KM_USER0);

	kvm_mmu_post_write(vcpu, gpa, bytes);

	return 1;

}



static int emulator_write_emulated(unsigned long addr,

				   unsigned long val,

				   const void *val,

				   unsigned int bytes,

				   struct x86_emulate_ctxt *ctxt)

{
@@ -1083,14 +1083,14 @@ static int emulator_write_emulated(unsigned long addr, 
	vcpu->mmio_phys_addr = gpa;

	vcpu->mmio_size = bytes;

	vcpu->mmio_is_write = 1;

	memcpy(vcpu->mmio_data, &val, bytes);

	memcpy(vcpu->mmio_data, val, bytes);



	return X86EMUL_CONTINUE;

}



static int emulator_cmpxchg_emulated(unsigned long addr,

				     unsigned long old,

				     unsigned long new,

				     const void *old,

				     const void *new,

				     unsigned int bytes,

				     struct x86_emulate_ctxt *ctxt)

{
@@ -1103,30 +1103,6 @@ static int emulator_cmpxchg_emulated(unsigned long addr, 
	return emulator_write_emulated(addr, new, bytes, ctxt);

}



#ifdef CONFIG_X86_32



static int emulator_cmpxchg8b_emulated(unsigned long addr,

				       unsigned long old_lo,

				       unsigned long old_hi,

				       unsigned long new_lo,

				       unsigned long new_hi,

				       struct x86_emulate_ctxt *ctxt)

{

	static int reported;

	int r;



	if (!reported) {

		reported = 1;

		printk(KERN_WARNING "kvm: emulating exchange8b as write\n");

	}

	r = emulator_write_emulated(addr, new_lo, 4, ctxt);

	if (r != X86EMUL_CONTINUE)

		return r;

	return emulator_write_emulated(addr+4, new_hi, 4, ctxt);

}



#endif



static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)

{

	return kvm_arch_ops->get_segment_base(vcpu, seg);
@@ -1201,9 +1177,6 @@ struct x86_emulate_ops emulate_ops = { 
	.read_emulated       = emulator_read_emulated,

	.write_emulated      = emulator_write_emulated,

	.cmpxchg_emulated    = emulator_cmpxchg_emulated,

#ifdef CONFIG_X86_32

	.cmpxchg8b_emulated  = emulator_cmpxchg8b_emulated,

#endif

};



int emulate_instruction(struct kvm_vcpu *vcpu,

drivers/kvm/x86_emulate.c

+9 −37
Original line number Diff line number Diff line
@@ -1045,7 +1045,7 @@ x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
			if ((rc = ops->write_std(

				     register_address(ctxt->ss_base,

						      _regs[VCPU_REGS_RSP]),

				     dst.val, dst.bytes, ctxt)) != 0)

				     &dst.val, dst.bytes, ctxt)) != 0)

				goto done;

			dst.val = dst.orig_val;	/* skanky: disable writeback */

			break;
@@ -1078,12 +1078,12 @@ x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		case OP_MEM:

			if (lock_prefix)

				rc = ops->cmpxchg_emulated((unsigned long)dst.

							   ptr, dst.orig_val,

							   dst.val, dst.bytes,

							   ptr, &dst.orig_val,

							   &dst.val, dst.bytes,

							   ctxt);

			else

				rc = ops->write_emulated((unsigned long)dst.ptr,

							 dst.val, dst.bytes,

							 &dst.val, dst.bytes,

							 ctxt);

			if (rc != 0)

				goto done;
@@ -1321,36 +1321,8 @@ x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		realmode_set_cr(ctxt->vcpu, modrm_reg, modrm_val, &_eflags);

		break;

	case 0xc7:		/* Grp9 (cmpxchg8b) */

#if defined(__i386__)

		{

			unsigned long old_lo, old_hi;

			if (((rc = ops->read_emulated(cr2 + 0, &old_lo, 4,

						      ctxt)) != 0)

			    || ((rc = ops->read_emulated(cr2 + 4, &old_hi, 4,

							 ctxt)) != 0))

				goto done;

			if ((old_lo != _regs[VCPU_REGS_RAX])

			    || (old_hi != _regs[VCPU_REGS_RDX])) {

				_regs[VCPU_REGS_RAX] = old_lo;

				_regs[VCPU_REGS_RDX] = old_hi;

				_eflags &= ~EFLG_ZF;

			} else if (ops->cmpxchg8b_emulated == NULL) {

				rc = X86EMUL_UNHANDLEABLE;

				goto done;

			} else {

				if ((rc = ops->cmpxchg8b_emulated(cr2, old_lo,

							  old_hi,

							  _regs[VCPU_REGS_RBX],

							  _regs[VCPU_REGS_RCX],

							  ctxt)) != 0)

					goto done;

				_eflags |= EFLG_ZF;

			}

			break;

		}

#elif defined(CONFIG_X86_64)

		{

			unsigned long old, new;

			u64 old, new;

			if ((rc = ops->read_emulated(cr2, &old, 8, ctxt)) != 0)

				goto done;

			if (((u32) (old >> 0) != (u32) _regs[VCPU_REGS_RAX]) ||
@@ -1359,15 +1331,15 @@ x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
				_regs[VCPU_REGS_RDX] = (u32) (old >> 32);

				_eflags &= ~EFLG_ZF;

			} else {

				new = (_regs[VCPU_REGS_RCX] << 32) | (u32) _regs[VCPU_REGS_RBX];

				if ((rc = ops->cmpxchg_emulated(cr2, old,

							  new, 8, ctxt)) != 0)

				new = ((u64)_regs[VCPU_REGS_RCX] << 32)

					| (u32) _regs[VCPU_REGS_RBX];

				if ((rc = ops->cmpxchg_emulated(cr2, &old,

							  &new, 8, ctxt)) != 0)

					goto done;

				_eflags |= EFLG_ZF;

			}

			break;

		}

#endif

	}

	goto writeback;

drivers/kvm/x86_emulate.h

+6 −26
Original line number Diff line number Diff line
@@ -59,8 +59,7 @@ struct x86_emulate_ops { 
	 *  @val:   [OUT] Value read from memory, zero-extended to 'u_long'.

	 *  @bytes: [IN ] Number of bytes to read from memory.

	 */

	int (*read_std)(unsigned long addr,

			unsigned long *val,

	int (*read_std)(unsigned long addr, void *val,

			unsigned int bytes, struct x86_emulate_ctxt * ctxt);



	/*
@@ -71,8 +70,7 @@ struct x86_emulate_ops { 
	 *                required).

	 *  @bytes: [IN ] Number of bytes to write to memory.

	 */

	int (*write_std)(unsigned long addr,

			 unsigned long val,

	int (*write_std)(unsigned long addr, const void *val,

			 unsigned int bytes, struct x86_emulate_ctxt * ctxt);



	/*
@@ -82,7 +80,7 @@ struct x86_emulate_ops { 
	 *  @bytes: [IN ] Number of bytes to read from memory.

	 */

	int (*read_emulated) (unsigned long addr,

			      unsigned long *val,

			      void *val,

			      unsigned int bytes,

			      struct x86_emulate_ctxt * ctxt);
@@ -94,7 +92,7 @@ struct x86_emulate_ops { 
	 *  @bytes: [IN ] Number of bytes to write to memory.

	 */

	int (*write_emulated) (unsigned long addr,

			       unsigned long val,

			       const void *val,

			       unsigned int bytes,

			       struct x86_emulate_ctxt * ctxt);
@@ -107,29 +105,11 @@ struct x86_emulate_ops { 
	 *  @bytes: [IN ] Number of bytes to access using CMPXCHG.

	 */

	int (*cmpxchg_emulated) (unsigned long addr,

				 unsigned long old,

				 unsigned long new,

				 const void *old,

				 const void *new,

				 unsigned int bytes,

				 struct x86_emulate_ctxt * ctxt);



	/*

	 * cmpxchg8b_emulated: Emulate an atomic (LOCKed) CMPXCHG8B operation on an

	 *                     emulated/special memory area.

	 *  @addr:  [IN ] Linear address to access.

	 *  @old:   [IN ] Value expected to be current at @addr.

	 *  @new:   [IN ] Value to write to @addr.

	 * NOTES:

	 *  1. This function is only ever called when emulating a real CMPXCHG8B.

	 *  2. This function is *never* called on x86/64 systems.

	 *  2. Not defining this function (i.e., specifying NULL) is equivalent

	 *     to defining a function that always returns X86EMUL_UNHANDLEABLE.

	 */

	int (*cmpxchg8b_emulated) (unsigned long addr,

				   unsigned long old_lo,

				   unsigned long old_hi,

				   unsigned long new_lo,

				   unsigned long new_hi,

				   struct x86_emulate_ctxt * ctxt);

};



struct cpu_user_regs;