This is a note to let you know that I've just added the patch titled

kvm/svm: Setup MCG_CAP on AMD properly

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kvm-svm-setup-mcg_cap-on-amd-properly.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Sun Mar 18 16:55:33 CET 2018

From: Borislav Petkov bp@suse.de Date: Sun, 26 Mar 2017 23:51:24 +0200 Subject: kvm/svm: Setup MCG_CAP on AMD properly

From: Borislav Petkov bp@suse.de

[ Upstream commit 74f169090b6f36b867c9df0454366dd9af6f62d1 ]

MCG_CAP[63:9] bits are reserved on AMD. However, on an AMD guest, this MSR returns 0x100010a. More specifically, bit 24 is set, which is simply wrong. That bit is MCG_SER_P and is present only on Intel. Thus, clean up the reserved bits in order not to confuse guests.

Signed-off-by: Borislav Petkov bp@suse.de Cc: Joerg Roedel joro@8bytes.org Cc: Paolo Bonzini pbonzini@redhat.com Cc: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/svm.c | 7 +++++++ 1 file changed, 7 insertions(+)

--- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -5449,6 +5449,12 @@ static inline void avic_post_state_resto avic_handle_ldr_update(vcpu); }

+static void svm_setup_mce(struct kvm_vcpu *vcpu) +{ + /* [63:9] are reserved. */ + vcpu->arch.mcg_cap &= 0x1ff; +} + static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .cpu_has_kvm_support = has_svm, .disabled_by_bios = is_disabled, @@ -5564,6 +5570,7 @@ static struct kvm_x86_ops svm_x86_ops __ .pmu_ops = &amd_pmu_ops, .deliver_posted_interrupt = svm_deliver_avic_intr, .update_pi_irte = svm_update_pi_irte, + .setup_mce = svm_setup_mce, };

static int __init svm_init(void)

Patches currently in stable-queue which might be from bp@suse.de are

queue-4.9/x86-mce-handle-broadcasted-mce-gracefully-with-kexec.patch queue-4.9/perf-stat-issue-a-hw-watchdog-disable-hint.patch queue-4.9/x86-mm-make-mmap-map_32bit-work-correctly.patch queue-4.9/edac-altera-fix-peripheral-warnings-for-cyclone5.patch queue-4.9/kvm-svm-setup-mcg_cap-on-amd-properly.patch queue-4.9/x86-mce-init-some-cpu-features-early.patch