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Commit 2dafc6c2 authored by Gleb Natapov's avatar Gleb Natapov Committed by Avi Kivity
Browse files

KVM: x86 emulator: Provide more callbacks for x86 emulator. 



Provide get_cached_descriptor(), set_cached_descriptor(),
get_segment_selector(), set_segment_selector(), get_gdt(),
write_std() callbacks.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent aca06a83

arch/x86/include/asm/kvm_emulate.h

+16 −0
Original line number Diff line number Diff line
@@ -62,6 +62,15 @@ struct x86_emulate_ops { 
	int (*read_std)(unsigned long addr, void *val,

			unsigned int bytes, struct kvm_vcpu *vcpu, u32 *error);



	/*

	 * write_std: Write bytes of standard (non-emulated/special) memory.

	 *            Used for descriptor writing.

	 *  @addr:  [IN ] Linear address to which to write.

	 *  @val:   [OUT] Value write to memory, zero-extended to 'u_long'.

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

	 */

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

			 unsigned int bytes, struct kvm_vcpu *vcpu, u32 *error);

	/*

	 * fetch: Read bytes of standard (non-emulated/special) memory.

	 *        Used for instruction fetch.
@@ -108,6 +117,13 @@ struct x86_emulate_ops { 
				const void *new,

				unsigned int bytes,

				struct kvm_vcpu *vcpu);

	bool (*get_cached_descriptor)(struct desc_struct *desc,

				      int seg, struct kvm_vcpu *vcpu);

	void (*set_cached_descriptor)(struct desc_struct *desc,

				      int seg, struct kvm_vcpu *vcpu);

	u16 (*get_segment_selector)(int seg, struct kvm_vcpu *vcpu);

	void (*set_segment_selector)(u16 sel, int seg, struct kvm_vcpu *vcpu);

	void (*get_gdt)(struct desc_ptr *dt, struct kvm_vcpu *vcpu);

	ulong (*get_cr)(int cr, struct kvm_vcpu *vcpu);

	void (*set_cr)(int cr, ulong val, struct kvm_vcpu *vcpu);

	int (*cpl)(struct kvm_vcpu *vcpu);

arch/x86/kvm/x86.c

+115 −15
Original line number Diff line number Diff line
@@ -3058,6 +3058,18 @@ static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v) 
	return kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, addr, len, v);

}



static void kvm_set_segment(struct kvm_vcpu *vcpu,

			struct kvm_segment *var, int seg)

{

	kvm_x86_ops->set_segment(vcpu, var, seg);

}



void kvm_get_segment(struct kvm_vcpu *vcpu,

		     struct kvm_segment *var, int seg)

{

	kvm_x86_ops->get_segment(vcpu, var, seg);

}



gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva, u32 *error)

{

	u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
@@ -3138,14 +3150,18 @@ static int kvm_read_guest_virt_system(gva_t addr, void *val, unsigned int bytes, 
	return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, 0, error);

}



static int kvm_write_guest_virt(gva_t addr, void *val, unsigned int bytes,

				struct kvm_vcpu *vcpu, u32 *error)

static int kvm_write_guest_virt_helper(gva_t addr, void *val,

				       unsigned int bytes,

				       struct kvm_vcpu *vcpu, u32 access,

				       u32 *error)

{

	void *data = val;

	int r = X86EMUL_CONTINUE;



	access |= PFERR_WRITE_MASK;



	while (bytes) {

		gpa_t gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, error);

		gpa_t gpa =  vcpu->arch.mmu.gva_to_gpa(vcpu, addr, access, error);

		unsigned offset = addr & (PAGE_SIZE-1);

		unsigned towrite = min(bytes, (unsigned)PAGE_SIZE - offset);

		int ret;
@@ -3168,6 +3184,19 @@ static int kvm_write_guest_virt(gva_t addr, void *val, unsigned int bytes, 
	return r;

}



static int kvm_write_guest_virt(gva_t addr, void *val, unsigned int bytes,

				struct kvm_vcpu *vcpu, u32 *error)

{

	u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;

	return kvm_write_guest_virt_helper(addr, val, bytes, vcpu, access, error);

}



static int kvm_write_guest_virt_system(gva_t addr, void *val,

				       unsigned int bytes,

				       struct kvm_vcpu *vcpu, u32 *error)

{

	return kvm_write_guest_virt_helper(addr, val, bytes, vcpu, 0, error);

}



static int emulator_read_emulated(unsigned long addr,

				  void *val,
@@ -3484,12 +3513,95 @@ static int emulator_get_cpl(struct kvm_vcpu *vcpu) 
	return kvm_x86_ops->get_cpl(vcpu);

}



static void emulator_get_gdt(struct desc_ptr *dt, struct kvm_vcpu *vcpu)

{

	kvm_x86_ops->get_gdt(vcpu, dt);

}



static bool emulator_get_cached_descriptor(struct desc_struct *desc, int seg,

					   struct kvm_vcpu *vcpu)

{

	struct kvm_segment var;



	kvm_get_segment(vcpu, &var, seg);



	if (var.unusable)

		return false;



	if (var.g)

		var.limit >>= 12;

	set_desc_limit(desc, var.limit);

	set_desc_base(desc, (unsigned long)var.base);

	desc->type = var.type;

	desc->s = var.s;

	desc->dpl = var.dpl;

	desc->p = var.present;

	desc->avl = var.avl;

	desc->l = var.l;

	desc->d = var.db;

	desc->g = var.g;



	return true;

}



static void emulator_set_cached_descriptor(struct desc_struct *desc, int seg,

					   struct kvm_vcpu *vcpu)

{

	struct kvm_segment var;



	/* needed to preserve selector */

	kvm_get_segment(vcpu, &var, seg);



	var.base = get_desc_base(desc);

	var.limit = get_desc_limit(desc);

	if (desc->g)

		var.limit = (var.limit << 12) | 0xfff;

	var.type = desc->type;

	var.present = desc->p;

	var.dpl = desc->dpl;

	var.db = desc->d;

	var.s = desc->s;

	var.l = desc->l;

	var.g = desc->g;

	var.avl = desc->avl;

	var.present = desc->p;

	var.unusable = !var.present;

	var.padding = 0;



	kvm_set_segment(vcpu, &var, seg);

	return;

}



static u16 emulator_get_segment_selector(int seg, struct kvm_vcpu *vcpu)

{

	struct kvm_segment kvm_seg;



	kvm_get_segment(vcpu, &kvm_seg, seg);

	return kvm_seg.selector;

}



static void emulator_set_segment_selector(u16 sel, int seg,

					  struct kvm_vcpu *vcpu)

{

	struct kvm_segment kvm_seg;



	kvm_get_segment(vcpu, &kvm_seg, seg);

	kvm_seg.selector = sel;

	kvm_set_segment(vcpu, &kvm_seg, seg);

}



static struct x86_emulate_ops emulate_ops = {

	.read_std            = kvm_read_guest_virt_system,

	.write_std           = kvm_write_guest_virt_system,

	.fetch               = kvm_fetch_guest_virt,

	.read_emulated       = emulator_read_emulated,

	.write_emulated      = emulator_write_emulated,

	.cmpxchg_emulated    = emulator_cmpxchg_emulated,

	.get_cached_descriptor = emulator_get_cached_descriptor,

	.set_cached_descriptor = emulator_set_cached_descriptor,

	.get_segment_selector = emulator_get_segment_selector,

	.set_segment_selector = emulator_set_segment_selector,

	.get_gdt             = emulator_get_gdt,

	.get_cr              = emulator_get_cr,

	.set_cr              = emulator_set_cr,

	.cpl                 = emulator_get_cpl,
@@ -4649,12 +4761,6 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs) 
	return 0;

}



void kvm_get_segment(struct kvm_vcpu *vcpu,

		     struct kvm_segment *var, int seg)

{

	kvm_x86_ops->get_segment(vcpu, var, seg);

}



void kvm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)

{

	struct kvm_segment cs;
@@ -4726,12 +4832,6 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, 
	return 0;

}



static void kvm_set_segment(struct kvm_vcpu *vcpu,

			struct kvm_segment *var, int seg)

{

	kvm_x86_ops->set_segment(vcpu, var, seg);

}



static void seg_desct_to_kvm_desct(struct desc_struct *seg_desc, u16 selector,

				   struct kvm_segment *kvm_desct)

{