Hello,
with kernel v6.16-rc5-121-gbc9ff192a6c9 I see this:
cat /sys/devices/system/cpu/vulnerabilities/tsa
Mitigation: Clear CPU buffers
dmesg | grep micro
[ 1.479203] microcode: Current revision: 0x0a20102e
[ 1.479206] microcode: Updated early from: 0x0a201016
So, this works.
but same machine with 6.6.97:
dmesg | grep micro
[ 0.451496] Transient Scheduler Attacks: Vulnerable: Clear CPU buffers
attempted, no microcode
[ 1.077149] microcode: Current revision: 0x0a20102e
[ 1.077152] microcode: Updated early from: 0x0a201016
so:
cat /sys/devices/system/cpu/vulnerabilities/tsa
Vulnerable: Clear CPU buffers attempted, no microcode
but it is switched on:
zcat /proc/config.gz | grep TSA
CONFIG_MITIGATION_TSA=y
And other stuff which need microcode works:
cat /sys/devices/system/cpu/vulnerabilities/spec_rstack_overflow
Mitigation: Safe RET
without microcode you wwould see:
Vulnerable: Safe RET, no microcode
6.12.37 broken too
6.15.6 works
v6.16-rc5-121-gbc9ff192a6c9 works
This is a:
processor : 11
vendor_id : AuthenticAMD
cpu family : 25
model : 33
model name : AMD Ryzen 5 5600X 6-Core Processor
stepping : 0
microcode : 0xa20102e
Is something missing in 6.6.y and 6.12.y?
Thomas
(already submitted @ Fedora; advised to post here to upstream as well)
-------- Forwarded Message --------
Subject: regression in 6.15.5: KVM guest launch FAILSs with missing CPU feature error (sbpb, ibpb-brtype)
Date: Sun, 13 Jul 2025 17:37:57 -0400
From: pgnd <pgnd(a)dev-mail.net>
Reply-To: pgnd(a)dev-mail.net
To: kernel(a)lists.fedoraproject.org
i'm seeing a regression on Fedora 42 kernel 6.15.4 -> 6.15.5 on AMD Ryzen 5 5600G host (x86_64)
kvm guests that launch ok under kernels 6.15.[3,4] fail with the following error when attempting to autostart under 6.15.5:
internal error: Failed to autostart VM: operation failed: guest CPU doesn't match specification: missing features: sbpb,ibpb-brtype
no changes made to libvirt, qemu, or VM defs between kernel versions.
re-booting to old kernel versions restores expected behavior.
maybe related (?) to recent changes in AMD CPU feature exposure / mitigation handling in kernel 6.15.5?
i've opened a bug:
https://bugzilla.redhat.com/show_bug.cgi?id=2379784
mptcp_connect.sh can be executed manually with "-m <MODE>" and "-C" to
make sure everything works as expected when using "mmap" and "sendfile"
modes instead of "poll", and with the MPTCP checksum support.
These modes should be validated, but they are not when the selftests are
executed via the kselftest helpers. It means that most CIs validating
these selftests, like NIPA for the net development trees and LKFT for
the stable ones, are not covering these modes.
To fix that, new test programs have been added, simply calling
mptcp_connect.sh with the right parameters.
The first patch can be backported up to v5.6, and the second one up to
v5.14.
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
---
Matthieu Baerts (NGI0) (2):
selftests: mptcp: connect: also cover alt modes
selftests: mptcp: connect: also cover checksum
tools/testing/selftests/net/mptcp/Makefile | 3 ++-
tools/testing/selftests/net/mptcp/mptcp_connect_checksum.sh | 4 ++++
tools/testing/selftests/net/mptcp/mptcp_connect_mmap.sh | 4 ++++
tools/testing/selftests/net/mptcp/mptcp_connect_sendfile.sh | 4 ++++
4 files changed, 14 insertions(+), 1 deletion(-)
---
base-commit: b640daa2822a39ff76e70200cb2b7b892b896dce
change-id: 20250714-net-mptcp-sft-connect-alt-c1aaf073ef4e
Best regards,
--
Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
vhost_vsock_alloc_skb() returns NULL for packets advertising a length
larger than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE in the packet header. However,
this is only checked once the SKB has been allocated and, if the length
in the packet header is zero, the SKB may not be freed immediately.
Hoist the size check before the SKB allocation so that an iovec larger
than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + the header size is rejected
outright. The subsequent check on the length field in the header can
then simply check that the allocated SKB is indeed large enough to hold
the packet.
Cc: <stable(a)vger.kernel.org>
Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Signed-off-by: Will Deacon <will(a)kernel.org>
---
drivers/vhost/vsock.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 802153e23073..66a0f060770e 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -344,6 +344,9 @@ vhost_vsock_alloc_skb(struct vhost_virtqueue *vq,
len = iov_length(vq->iov, out);
+ if (len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + VIRTIO_VSOCK_SKB_HEADROOM)
+ return NULL;
+
/* len contains both payload and hdr */
skb = virtio_vsock_alloc_skb(len, GFP_KERNEL);
if (!skb)
@@ -367,8 +370,7 @@ vhost_vsock_alloc_skb(struct vhost_virtqueue *vq,
return skb;
/* The pkt is too big or the length in the header is invalid */
- if (payload_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE ||
- payload_len + sizeof(*hdr) > len) {
+ if (payload_len + sizeof(*hdr) > len) {
kfree_skb(skb);
return NULL;
}
--
2.50.0.727.gbf7dc18ff4-goog
I'm announcing the release of the 6.12.38 kernel.
Only users of AMD x86-based processors need to upgrade, all others may
skip this release.
The updated 6.12.y git tree can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-6.12.y
and can be browsed at the normal kernel.org git web browser:
https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary
thanks,
greg k-h
------------
Makefile | 2 +-
arch/x86/kernel/cpu/amd.c | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
Borislav Petkov (AMD) (1):
x86/CPU/AMD: Properly check the TSA microcode
Greg Kroah-Hartman (1):
Linux 6.12.38
I'm announcing the release of the 6.6.98 kernel.
Only users of AMD x86-based processors need to upgrade, all others may
skip this release.
The updated 6.6.y git tree can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-6.6.y
and can be browsed at the normal kernel.org git web browser:
https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary
thanks,
greg k-h
------------
Makefile | 2 +-
arch/x86/kernel/cpu/amd.c | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
Borislav Petkov (AMD) (1):
x86/CPU/AMD: Properly check the TSA microcode
Greg Kroah-Hartman (1):
Linux 6.6.98
I'm announcing the release of the 6.1.145 kernel.
Only users of AMD x86-based processors need to upgrade, all others may
skip this release.
The updated 6.1.y git tree can be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-6.1.y
and can be browsed at the normal kernel.org git web browser:
https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary
thanks,
greg k-h
------------
Makefile | 2 +-
arch/x86/kernel/cpu/amd.c | 5 +++--
2 files changed, 4 insertions(+), 3 deletions(-)
Borislav Petkov (AMD) (1):
x86/CPU/AMD: Properly check the TSA microcode
Greg Kroah-Hartman (1):
Linux 6.1.145