linux-kernel - [PATCH] selftests: KVM: avoid failures due to reserved HyperTransport region

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-next>] [day] [month] [year] [list]

Message-Id: <20210805105423.412878-1-pbonzini@redhat.com>
Date:   Thu,  5 Aug 2021 06:54:23 -0400
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     stable@...r.kernel.org, David Matlack <dmatlack@...gle.com>,
        Maxim Levitsky <mlevitsk@...hat.com>
Subject: [PATCH] selftests: KVM: avoid failures due to reserved HyperTransport region

Accessing guest physical addresses at 0xFFFD_0000_0000 and above causes
a failure on AMD processors because those addresses are reserved by
HyperTransport (this is not documented).  Avoid selftests failures
by reserving those guest physical addresses.

Fixes: ef4c9f4f6546 ("KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()")
Cc: stable@...r.kernel.org
Cc: David Matlack <dmatlack@...gle.com>
Reported-by: Maxim Levitsky <mlevitsk@...hat.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 10a8ed691c66..d995cc9836ee 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -309,6 +309,12 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
 	/* Limit physical addresses to PA-bits. */
 	vm->max_gfn = ((1ULL << vm->pa_bits) >> vm->page_shift) - 1;
 
+#ifdef __x86_64__
+	/* Avoid reserved HyperTransport region on AMD processors.  */
+	if (vm->pa_bits == 48)
+		vm->max_gfn = 0xfffcfffff;
+#endif
+
 	/* Allocate and setup memory for guest. */
 	vm->vpages_mapped = sparsebit_alloc();
 	if (phy_pages != 0)
-- 
2.27.0