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Commit 8bf46a39 authored by Janis Schoetterl-Glausch's avatar Janis Schoetterl-Glausch Committed by Greg Kroah-Hartman
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KVM: s390: gaccess: Refactor gpa and length calculation 



[ Upstream commit 416e7f0c9d613bf84e182eba9547ae8f9f5bfa4c ]

Improve readability by renaming the length variable and
not calculating the offset manually.

Signed-off-by: default avatarJanis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Message-Id: <20211126164549.7046-2-scgl@linux.ibm.com>
Signed-off-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Stable-dep-of: e8061f06185b ("KVM: s390: gaccess: Check if guest address is in memslot")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent b6a638cb

arch/s390/kvm/gaccess.c

+17 −15
Original line number Diff line number Diff line
@@ -831,8 +831,9 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 
		 unsigned long len, enum gacc_mode mode)

{

	psw_t *psw = &vcpu->arch.sie_block->gpsw;

	unsigned long _len, nr_pages, gpa, idx;

	unsigned long nr_pages, gpa, idx;

	unsigned long pages_array[2];

	unsigned int fragment_len;

	unsigned long *pages;

	int need_ipte_lock;

	union asce asce;
@@ -855,15 +856,15 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 
		ipte_lock(vcpu);

	rc = guest_page_range(vcpu, ga, ar, pages, nr_pages, asce, mode);

	for (idx = 0; idx < nr_pages && !rc; idx++) {

		gpa = *(pages + idx) + (ga & ~PAGE_MASK);

		_len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);

		gpa = pages[idx] + offset_in_page(ga);

		fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);

		if (mode == GACC_STORE)

			rc = kvm_write_guest(vcpu->kvm, gpa, data, _len);

			rc = kvm_write_guest(vcpu->kvm, gpa, data, fragment_len);

		else

			rc = kvm_read_guest(vcpu->kvm, gpa, data, _len);

		len -= _len;

		ga += _len;

		data += _len;

			rc = kvm_read_guest(vcpu->kvm, gpa, data, fragment_len);

		len -= fragment_len;

		ga += fragment_len;

		data += fragment_len;

	}

	if (need_ipte_lock)

		ipte_unlock(vcpu);
@@ -875,19 +876,20 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 
int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,

		      void *data, unsigned long len, enum gacc_mode mode)

{

	unsigned long _len, gpa;

	unsigned int fragment_len;

	unsigned long gpa;

	int rc = 0;



	while (len && !rc) {

		gpa = kvm_s390_real_to_abs(vcpu, gra);

		_len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);

		fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);

		if (mode)

			rc = write_guest_abs(vcpu, gpa, data, _len);

			rc = write_guest_abs(vcpu, gpa, data, fragment_len);

		else

			rc = read_guest_abs(vcpu, gpa, data, _len);

		len -= _len;

		gra += _len;

		data += _len;

			rc = read_guest_abs(vcpu, gpa, data, fragment_len);

		len -= fragment_len;

		gra += fragment_len;

		data += fragment_len;

	}

	return rc;

}