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Commit 6ff887b8 authored by Suraj Jitindar Singh's avatar Suraj Jitindar Singh Committed by Paul Mackerras
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KVM: PPC: Book3S: Introduce new hcall H_COPY_TOFROM_GUEST to access quadrants 1 & 2 



A guest cannot access quadrants 1 or 2 as this would result in an
exception. Thus introduce the hcall H_COPY_TOFROM_GUEST to be used by a
guest when it wants to perform an access to quadrants 1 or 2, for
example when it wants to access memory for one of its nested guests.

Also provide an implementation for the kvm-hv module.

Signed-off-by: default avatarSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 873db2cd

arch/powerpc/include/asm/hvcall.h

+1 −0
Original line number Diff line number Diff line
@@ -335,6 +335,7 @@ 
#define H_SET_PARTITION_TABLE	0xF800

#define H_ENTER_NESTED		0xF804

#define H_TLB_INVALIDATE	0xF808

#define H_COPY_TOFROM_GUEST	0xF80C



/* Values for 2nd argument to H_SET_MODE */

#define H_SET_MODE_RESOURCE_SET_CIABR		1

arch/powerpc/include/asm/kvm_book3s.h

+4 −0
Original line number Diff line number Diff line
@@ -188,6 +188,9 @@ extern int kvmppc_book3s_hcall_implemented(struct kvm *kvm, unsigned long hc); 
extern int kvmppc_book3s_radix_page_fault(struct kvm_run *run,

			struct kvm_vcpu *vcpu,

			unsigned long ea, unsigned long dsisr);

extern unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,

					gva_t eaddr, void *to, void *from,

					unsigned long n);

extern long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,

					void *to, unsigned long n);

extern long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,
@@ -301,6 +304,7 @@ long kvmhv_nested_init(void); 
void kvmhv_nested_exit(void);

void kvmhv_vm_nested_init(struct kvm *kvm);

long kvmhv_set_partition_table(struct kvm_vcpu *vcpu);

long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu);

void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1);

void kvmhv_release_all_nested(struct kvm *kvm);

long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu);

arch/powerpc/kvm/book3s_64_mmu_radix.c

+4 −3
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ 
 */

static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };



static unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,

unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,

					      gva_t eaddr, void *to, void *from,

					      unsigned long n)

{
@@ -82,6 +82,7 @@ static unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid, 


	return ret;

}

EXPORT_SYMBOL_GPL(__kvmhv_copy_tofrom_guest_radix);



static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr,

					  void *to, void *from, unsigned long n)

arch/powerpc/kvm/book3s_hv.c

+5 −1
Original line number Diff line number Diff line
@@ -996,7 +996,11 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu) 
		if (nesting_enabled(vcpu->kvm))

			ret = kvmhv_do_nested_tlbie(vcpu);

		break;



	case H_COPY_TOFROM_GUEST:

		ret = H_FUNCTION;

		if (nesting_enabled(vcpu->kvm))

			ret = kvmhv_copy_tofrom_guest_nested(vcpu);

		break;

	default:

		return RESUME_HOST;

	}

arch/powerpc/kvm/book3s_hv_nested.c

+75 −0
Original line number Diff line number Diff line
@@ -461,6 +461,81 @@ long kvmhv_set_partition_table(struct kvm_vcpu *vcpu) 
	return ret;

}



/*

 * Handle the H_COPY_TOFROM_GUEST hcall.

 * r4 = L1 lpid of nested guest

 * r5 = pid

 * r6 = eaddr to access

 * r7 = to buffer (L1 gpa)

 * r8 = from buffer (L1 gpa)

 * r9 = n bytes to copy

 */

long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu)

{

	struct kvm_nested_guest *gp;

	int l1_lpid = kvmppc_get_gpr(vcpu, 4);

	int pid = kvmppc_get_gpr(vcpu, 5);

	gva_t eaddr = kvmppc_get_gpr(vcpu, 6);

	gpa_t gp_to = (gpa_t) kvmppc_get_gpr(vcpu, 7);

	gpa_t gp_from = (gpa_t) kvmppc_get_gpr(vcpu, 8);

	void *buf;

	unsigned long n = kvmppc_get_gpr(vcpu, 9);

	bool is_load = !!gp_to;

	long rc;



	if (gp_to && gp_from) /* One must be NULL to determine the direction */

		return H_PARAMETER;



	if (eaddr & (0xFFFUL << 52))

		return H_PARAMETER;



	buf = kzalloc(n, GFP_KERNEL);

	if (!buf)

		return H_NO_MEM;



	gp = kvmhv_get_nested(vcpu->kvm, l1_lpid, false);

	if (!gp) {

		rc = H_PARAMETER;

		goto out_free;

	}



	mutex_lock(&gp->tlb_lock);



	if (is_load) {

		/* Load from the nested guest into our buffer */

		rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,

						     eaddr, buf, NULL, n);

		if (rc)

			goto not_found;



		/* Write what was loaded into our buffer back to the L1 guest */

		rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n);

		if (rc)

			goto not_found;

	} else {

		/* Load the data to be stored from the L1 guest into our buf */

		rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n);

		if (rc)

			goto not_found;



		/* Store from our buffer into the nested guest */

		rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,

						     eaddr, NULL, buf, n);

		if (rc)

			goto not_found;

	}



out_unlock:

	mutex_unlock(&gp->tlb_lock);

	kvmhv_put_nested(gp);

out_free:

	kfree(buf);

	return rc;

not_found:

	rc = H_NOT_FOUND;

	goto out_unlock;

}



/*

 * Reload the partition table entry for a guest.

 * Caller must hold gp->tlb_lock.