linux-kernel - [PATCH v2 3/3] KVM: s390: gaccess: Cleanup access to guest frames

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20211028135556.1793063-4-scgl@linux.ibm.com>
Date:   Thu, 28 Oct 2021 15:55:56 +0200
From:   Janis Schoetterl-Glausch <scgl@...ux.ibm.com>
To:     Christian Borntraeger <borntraeger@...ibm.com>,
        Janosch Frank <frankja@...ux.ibm.com>,
        Heiko Carstens <hca@...ux.ibm.com>,
        Vasily Gorbik <gor@...ux.ibm.com>
Cc:     Janis Schoetterl-Glausch <scgl@...ux.ibm.com>,
        David Hildenbrand <david@...hat.com>,
        Claudio Imbrenda <imbrenda@...ux.ibm.com>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        kvm@...r.kernel.org, linux-s390@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2 3/3] KVM: s390: gaccess: Cleanup access to guest frames

Introduce a helper function for guest frame access.

Signed-off-by: Janis Schoetterl-Glausch <scgl@...ux.ibm.com>
---
 arch/s390/kvm/gaccess.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index f0848c37b003..9a633310b6fe 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -866,6 +866,20 @@ static int guest_range_to_gpas(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
 	return 0;
 }
 
+static int access_guest_page(struct kvm *kvm, enum gacc_mode mode, gpa_t gpa,
+			      void *data, unsigned int len)
+{
+	const unsigned int offset = offset_in_page(gpa);
+	const gfn_t gfn = gpa_to_gfn(gpa);
+	int rc;
+
+	if (mode == GACC_STORE)
+		rc = kvm_write_guest_page(kvm, gfn, data, offset, len);
+	else
+		rc = kvm_read_guest_page(kvm, gfn, data, offset, len);
+	return rc;
+}
+
 int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
 		 unsigned long len, enum gacc_mode mode)
 {
@@ -896,10 +910,7 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
 	rc = guest_range_to_gpas(vcpu, ga, ar, gpas, len, asce, mode);
 	for (idx = 0; idx < nr_pages && !rc; idx++) {
 		fragment_len = min(PAGE_SIZE - offset_in_page(gpas[idx]), len);
-		if (mode == GACC_STORE)
-			rc = kvm_write_guest(vcpu->kvm, gpas[idx], data, fragment_len);
-		else
-			rc = kvm_read_guest(vcpu->kvm, gpas[idx], data, fragment_len);
+		rc = access_guest_page(vcpu->kvm, mode, gpas[idx], data, fragment_len);
 		len -= fragment_len;
 		data += fragment_len;
 	}
@@ -920,10 +931,7 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
 	while (len && !rc) {
 		gpa = kvm_s390_real_to_abs(vcpu, gra);
 		fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);
-		if (mode)
-			rc = write_guest_abs(vcpu, gpa, data, fragment_len);
-		else
-			rc = read_guest_abs(vcpu, gpa, data, fragment_len);
+		rc = access_guest_page(vcpu->kvm, mode, gpa, data, fragment_len);
 		len -= fragment_len;
 		gra += fragment_len;
 		data += fragment_len;
-- 
2.25.1