Commit 6ca00dfa authored by Liran Alon's avatar Liran Alon Committed by Paolo Bonzini
Browse files

KVM: x86: Modify struct kvm_nested_state to have explicit fields for data 



Improve the KVM_{GET,SET}_NESTED_STATE structs by detailing the format
of VMX nested state data in a struct.

In order to avoid changing the ioctl values of
KVM_{GET,SET}_NESTED_STATE, there is a need to preserve
sizeof(struct kvm_nested_state). This is done by defining the data
struct as "data.vmx[0]". It was the most elegant way I found to
preserve struct size while still keeping struct readable and easy to
maintain. It does have a misfortunate side-effect that now it has to be
accessed as "data.vmx[0]" rather than just "data.vmx".

Because we are already modifying these structs, I also modified the
following:
* Define the "format" field values as macros.
* Rename vmcs_pa to vmcs12_pa for better readability.

Signed-off-by: default avatarLiran Alon <liran.alon@oracle.com>
[Remove SVM stubs, add KVM_STATE_NESTED_VMX_VMCS12_SIZE. - Paolo]
Reviewed-by: default avatarLiran Alon <liran.alon@oracle.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 76e3bcdb

Documentation/virtual/kvm/api.txt

+31 −15
Original line number Diff line number Diff line
@@ -3857,43 +3857,59 @@ Type: vcpu ioctl 
Parameters: struct kvm_nested_state (in/out)

Returns: 0 on success, -1 on error

Errors:

  E2BIG:     the total state size (including the fixed-size part of struct

             kvm_nested_state) exceeds the value of 'size' specified by

  E2BIG:     the total state size exceeds the value of 'size' specified by

             the user; the size required will be written into size.



struct kvm_nested_state {

	__u16 flags;

	__u16 format;

	__u32 size;



	union {

		struct kvm_vmx_nested_state vmx;

		struct kvm_svm_nested_state svm;

		struct kvm_vmx_nested_state_hdr vmx;

		struct kvm_svm_nested_state_hdr svm;



		/* Pad the header to 128 bytes.  */

		__u8 pad[120];

	};

	__u8 data[0];

	} hdr;



	union {

		struct kvm_vmx_nested_state_data vmx[0];

		struct kvm_svm_nested_state_data svm[0];

	} data;

};



#define KVM_STATE_NESTED_GUEST_MODE	0x00000001

#define KVM_STATE_NESTED_RUN_PENDING	0x00000002

#define KVM_STATE_NESTED_EVMCS		0x00000004



#define KVM_STATE_NESTED_SMM_GUEST_MODE	0x00000001

#define KVM_STATE_NESTED_SMM_VMXON	0x00000002

#define KVM_STATE_NESTED_FORMAT_VMX		0

#define KVM_STATE_NESTED_FORMAT_SVM		1



struct kvm_vmx_nested_state {

#define KVM_STATE_NESTED_VMX_VMCS_SIZE		0x1000



#define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE	0x00000001

#define KVM_STATE_NESTED_VMX_SMM_VMXON		0x00000002



struct kvm_vmx_nested_state_hdr {

	__u64 vmxon_pa;

	__u64 vmcs_pa;

	__u64 vmcs12_pa;



	struct {

		__u16 flags;

	} smm;

};



struct kvm_vmx_nested_state_data {

	__u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];

	__u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];

};



This ioctl copies the vcpu's nested virtualization state from the kernel to

userspace.



The maximum size of the state, including the fixed-size part of struct

kvm_nested_state, can be retrieved by passing KVM_CAP_NESTED_STATE to

the KVM_CHECK_EXTENSION ioctl().

The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE

to the KVM_CHECK_EXTENSION ioctl().



4.115 KVM_SET_NESTED_STATE
@@ -3903,8 +3919,8 @@ Type: vcpu ioctl 
Parameters: struct kvm_nested_state (in)

Returns: 0 on success, -1 on error



This copies the vcpu's kvm_nested_state struct from userspace to the kernel.  For

the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE.

This copies the vcpu's kvm_nested_state struct from userspace to the kernel.

For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE.



4.116 KVM_(UN)REGISTER_COALESCED_MMIO

arch/x86/include/uapi/asm/kvm.h

+22 −11
Original line number Diff line number Diff line
@@ -383,6 +383,9 @@ struct kvm_sync_regs { 
#define KVM_X86_QUIRK_LAPIC_MMIO_HOLE	(1 << 2)

#define KVM_X86_QUIRK_OUT_7E_INC_RIP	(1 << 3)



#define KVM_STATE_NESTED_FORMAT_VMX	0

#define KVM_STATE_NESTED_FORMAT_SVM	1	/* unused */



#define KVM_STATE_NESTED_GUEST_MODE	0x00000001

#define KVM_STATE_NESTED_RUN_PENDING	0x00000002

#define KVM_STATE_NESTED_EVMCS		0x00000004
@@ -390,9 +393,16 @@ struct kvm_sync_regs { 
#define KVM_STATE_NESTED_SMM_GUEST_MODE	0x00000001

#define KVM_STATE_NESTED_SMM_VMXON	0x00000002



struct kvm_vmx_nested_state {

#define KVM_STATE_NESTED_VMX_VMCS_SIZE	0x1000



struct kvm_vmx_nested_state_data {

	__u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];

	__u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];

};



struct kvm_vmx_nested_state_hdr {

	__u64 vmxon_pa;

	__u64 vmcs_pa;

	__u64 vmcs12_pa;



	struct {

		__u16 flags;
@@ -401,24 +411,25 @@ struct kvm_vmx_nested_state { 


/* for KVM_CAP_NESTED_STATE */

struct kvm_nested_state {

	/* KVM_STATE_* flags */

	__u16 flags;



	/* 0 for VMX, 1 for SVM.  */

	__u16 format;



	/* 128 for SVM, 128 + VMCS size for VMX.  */

	__u32 size;



	union {

		/* VMXON, VMCS */

		struct kvm_vmx_nested_state vmx;

		struct kvm_vmx_nested_state_hdr vmx;



		/* Pad the header to 128 bytes.  */

		__u8 pad[120];

	};

	} hdr;



	__u8 data[0];

	/*

	 * Define data region as 0 bytes to preserve backwards-compatability

	 * to old definition of kvm_nested_state in order to avoid changing

	 * KVM_{GET,PUT}_NESTED_STATE ioctl values.

	 */

	union {

		struct kvm_vmx_nested_state_data vmx[0];

	} data;

};



#endif /* _ASM_X86_KVM_H */

arch/x86/kvm/vmx/nested.c

+44 −35
Original line number Diff line number Diff line
@@ -5226,14 +5226,16 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, 
	struct vmcs12 *vmcs12;

	struct kvm_nested_state kvm_state = {

		.flags = 0,

		.format = 0,

		.format = KVM_STATE_NESTED_FORMAT_VMX,

		.size = sizeof(kvm_state),

		.vmx.vmxon_pa = -1ull,

		.vmx.vmcs_pa = -1ull,

		.hdr.vmx.vmxon_pa = -1ull,

		.hdr.vmx.vmcs12_pa = -1ull,

	};

	struct kvm_vmx_nested_state_data __user *user_vmx_nested_state =

		&user_kvm_nested_state->data.vmx[0];



	if (!vcpu)

		return kvm_state.size + 2 * VMCS12_SIZE;

		return kvm_state.size + sizeof(*user_vmx_nested_state);



	vmx = to_vmx(vcpu);

	vmcs12 = get_vmcs12(vcpu);
@@ -5243,23 +5245,23 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, 


	if (nested_vmx_allowed(vcpu) &&

	    (vmx->nested.vmxon || vmx->nested.smm.vmxon)) {

		kvm_state.vmx.vmxon_pa = vmx->nested.vmxon_ptr;

		kvm_state.vmx.vmcs_pa = vmx->nested.current_vmptr;

		kvm_state.hdr.vmx.vmxon_pa = vmx->nested.vmxon_ptr;

		kvm_state.hdr.vmx.vmcs12_pa = vmx->nested.current_vmptr;



		if (vmx_has_valid_vmcs12(vcpu)) {

			kvm_state.size += VMCS12_SIZE;

			kvm_state.size += sizeof(user_vmx_nested_state->vmcs12);



			if (is_guest_mode(vcpu) &&

			    nested_cpu_has_shadow_vmcs(vmcs12) &&

			    vmcs12->vmcs_link_pointer != -1ull)

				kvm_state.size += VMCS12_SIZE;

				kvm_state.size += sizeof(user_vmx_nested_state->shadow_vmcs12);

		}



		if (vmx->nested.smm.vmxon)

			kvm_state.vmx.smm.flags |= KVM_STATE_NESTED_SMM_VMXON;

			kvm_state.hdr.vmx.smm.flags |= KVM_STATE_NESTED_SMM_VMXON;



		if (vmx->nested.smm.guest_mode)

			kvm_state.vmx.smm.flags |= KVM_STATE_NESTED_SMM_GUEST_MODE;

			kvm_state.hdr.vmx.smm.flags |= KVM_STATE_NESTED_SMM_GUEST_MODE;



		if (is_guest_mode(vcpu)) {

			kvm_state.flags |= KVM_STATE_NESTED_GUEST_MODE;
@@ -5294,16 +5296,19 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, 
			copy_shadow_to_vmcs12(vmx);

	}



	BUILD_BUG_ON(sizeof(user_vmx_nested_state->vmcs12) < VMCS12_SIZE);

	BUILD_BUG_ON(sizeof(user_vmx_nested_state->shadow_vmcs12) < VMCS12_SIZE);



	/*

	 * Copy over the full allocated size of vmcs12 rather than just the size

	 * of the struct.

	 */

	if (copy_to_user(user_kvm_nested_state->data, vmcs12, VMCS12_SIZE))

	if (copy_to_user(user_vmx_nested_state->vmcs12, vmcs12, VMCS12_SIZE))

		return -EFAULT;



	if (nested_cpu_has_shadow_vmcs(vmcs12) &&

	    vmcs12->vmcs_link_pointer != -1ull) {

		if (copy_to_user(user_kvm_nested_state->data + VMCS12_SIZE,

		if (copy_to_user(user_vmx_nested_state->shadow_vmcs12,

				 get_shadow_vmcs12(vcpu), VMCS12_SIZE))

			return -EFAULT;

	}
@@ -5331,33 +5336,35 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, 
	struct vcpu_vmx *vmx = to_vmx(vcpu);

	struct vmcs12 *vmcs12;

	u32 exit_qual;

	struct kvm_vmx_nested_state_data __user *user_vmx_nested_state =

		&user_kvm_nested_state->data.vmx[0];

	int ret;



	if (kvm_state->format != 0)

	if (kvm_state->format != KVM_STATE_NESTED_FORMAT_VMX)

		return -EINVAL;



	if (!nested_vmx_allowed(vcpu))

		return kvm_state->vmx.vmxon_pa == -1ull ? 0 : -EINVAL;

		return kvm_state->hdr.vmx.vmxon_pa == -1ull ? 0 : -EINVAL;



	if (kvm_state->vmx.vmxon_pa == -1ull) {

		if (kvm_state->vmx.smm.flags)

	if (kvm_state->hdr.vmx.vmxon_pa == -1ull) {

		if (kvm_state->hdr.vmx.smm.flags)

			return -EINVAL;



		if (kvm_state->vmx.vmcs_pa != -1ull)

		if (kvm_state->hdr.vmx.vmcs12_pa != -1ull)

			return -EINVAL;



		vmx_leave_nested(vcpu);

		return 0;

	}



	if (!page_address_valid(vcpu, kvm_state->vmx.vmxon_pa))

	if (!page_address_valid(vcpu, kvm_state->hdr.vmx.vmxon_pa))

		return -EINVAL;



	if ((kvm_state->vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE) &&

	if ((kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE) &&

	    (kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE))

		return -EINVAL;



	if (kvm_state->vmx.smm.flags &

	if (kvm_state->hdr.vmx.smm.flags &

	    ~(KVM_STATE_NESTED_SMM_GUEST_MODE | KVM_STATE_NESTED_SMM_VMXON))

		return -EINVAL;
@@ -5366,21 +5373,21 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, 
	 * nor can VMLAUNCH/VMRESUME be pending.  Outside SMM, SMM flags

	 * must be zero.

	 */

	if (is_smm(vcpu) ? kvm_state->flags : kvm_state->vmx.smm.flags)

	if (is_smm(vcpu) ? kvm_state->flags : kvm_state->hdr.vmx.smm.flags)

		return -EINVAL;



	if ((kvm_state->vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE) &&

	    !(kvm_state->vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON))

	if ((kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE) &&

	    !(kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON))

		return -EINVAL;



	vmx_leave_nested(vcpu);

	if (kvm_state->vmx.vmxon_pa == -1ull)

	if (kvm_state->hdr.vmx.vmxon_pa == -1ull)

		return 0;



	if (kvm_state->flags & KVM_STATE_NESTED_EVMCS)

		nested_enable_evmcs(vcpu, NULL);



	vmx->nested.vmxon_ptr = kvm_state->vmx.vmxon_pa;

	vmx->nested.vmxon_ptr = kvm_state->hdr.vmx.vmxon_pa;

	ret = enter_vmx_operation(vcpu);

	if (ret)

		return ret;
@@ -5389,12 +5396,12 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, 
	if (kvm_state->size < sizeof(*kvm_state) + sizeof(*vmcs12))

		return 0;



	if (kvm_state->vmx.vmcs_pa != -1ull) {

		if (kvm_state->vmx.vmcs_pa == kvm_state->vmx.vmxon_pa ||

		    !page_address_valid(vcpu, kvm_state->vmx.vmcs_pa))

	if (kvm_state->hdr.vmx.vmcs12_pa != -1ull) {

		if (kvm_state->hdr.vmx.vmcs12_pa == kvm_state->hdr.vmx.vmxon_pa ||

		    !page_address_valid(vcpu, kvm_state->hdr.vmx.vmcs12_pa))

			return -EINVAL;



		set_current_vmptr(vmx, kvm_state->vmx.vmcs_pa);

		set_current_vmptr(vmx, kvm_state->hdr.vmx.vmcs12_pa);

	} else if (kvm_state->flags & KVM_STATE_NESTED_EVMCS) {

		/*

		 * Sync eVMCS upon entry as we may not have
@@ -5405,16 +5412,16 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, 
		return -EINVAL;

	}



	if (kvm_state->vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON) {

	if (kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON) {

		vmx->nested.smm.vmxon = true;

		vmx->nested.vmxon = false;



		if (kvm_state->vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE)

		if (kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE)

			vmx->nested.smm.guest_mode = true;

	}



	vmcs12 = get_vmcs12(vcpu);

	if (copy_from_user(vmcs12, user_kvm_nested_state->data, sizeof(*vmcs12)))

	if (copy_from_user(vmcs12, user_vmx_nested_state->vmcs12, sizeof(*vmcs12)))

		return -EFAULT;



	if (vmcs12->hdr.revision_id != VMCS12_REVISION)
@@ -5431,12 +5438,14 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, 
	    vmcs12->vmcs_link_pointer != -1ull) {

		struct vmcs12 *shadow_vmcs12 = get_shadow_vmcs12(vcpu);



		if (kvm_state->size < sizeof(*kvm_state) + VMCS12_SIZE + sizeof(*vmcs12))

		if (kvm_state->size <

		    sizeof(*kvm_state) +

		    sizeof(user_vmx_nested_state->vmcs12) + sizeof(*shadow_vmcs12))

			goto error_guest_mode;



		if (copy_from_user(shadow_vmcs12,

				   user_kvm_nested_state->data + VMCS12_SIZE,

				   sizeof(*vmcs12))) {

				   user_vmx_nested_state->shadow_vmcs12,

				   sizeof(*shadow_vmcs12))) {

			ret = -EFAULT;

			goto error_guest_mode;

		}

arch/x86/kvm/vmx/vmcs12.h

+3 −2
Original line number Diff line number Diff line
@@ -201,9 +201,10 @@ struct __packed vmcs12 { 
/*

 * VMCS12_SIZE is the number of bytes L1 should allocate for the VMXON region

 * and any VMCS region. Although only sizeof(struct vmcs12) are used by the

 * current implementation, 4K are reserved to avoid future complications.

 * current implementation, 4K are reserved to avoid future complications and

 * to preserve userspace ABI.

 */

#define VMCS12_SIZE 0x1000

#define VMCS12_SIZE		KVM_STATE_NESTED_VMX_VMCS_SIZE



/*

 * VMCS12_MAX_FIELD_INDEX is the highest index value used in any

tools/arch/x86/include/uapi/asm/kvm.h

+1 −1
Original line number Diff line number Diff line
@@ -392,7 +392,7 @@ struct kvm_sync_regs { 


struct kvm_vmx_nested_state {

	__u64 vmxon_pa;

	__u64 vmcs_pa;

	__u64 vmcs12_pa;



	struct {

		__u16 flags;

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