diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0085-KVM-lapic-stop-advertising-DIRECTED_EOI-when-in-kern.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0085-KVM-lapic-stop-advertising-DIRECTED_EOI-when-in-kern.patch | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0085-KVM-lapic-stop-advertising-DIRECTED_EOI-when-in-kern.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0085-KVM-lapic-stop-advertising-DIRECTED_EOI-when-in-kern.patch new file mode 100644 index 00000000..db300b21 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0085-KVM-lapic-stop-advertising-DIRECTED_EOI-when-in-kern.patch @@ -0,0 +1,56 @@ +From 2ece92e70fbd29fd14c1add63648b7154521b473 Mon Sep 17 00:00:00 2001 +From: Vitaly Kuznetsov <vkuznets@redhat.com> +Date: Fri, 9 Feb 2018 14:01:33 +0100 +Subject: [PATCH 85/93] KVM: lapic: stop advertising DIRECTED_EOI when + in-kernel IOAPIC is in use +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +[ Upstream commit 0bcc3fb95b97ac2ca223a5a870287b37f56265ac ] + +Devices which use level-triggered interrupts under Windows 2016 with +Hyper-V role enabled don't work: Windows disables EOI broadcast in SPIV +unconditionally. Our in-kernel IOAPIC implementation emulates an old IOAPIC +version which has no EOI register so EOI never happens. + +The issue was discovered and discussed a while ago: +https://www.spinics.net/lists/kvm/msg148098.html + +While this is a guest OS bug (it should check that IOAPIC has the required +capabilities before disabling EOI broadcast) we can workaround it in KVM: +advertising DIRECTED_EOI with in-kernel IOAPIC makes little sense anyway. + +Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> +Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> +Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/kvm/lapic.c | 10 +++++++++- + 1 file changed, 9 insertions(+), 1 deletion(-) + +diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c +index 650ff4a..d99e13d 100644 +--- a/arch/x86/kvm/lapic.c ++++ b/arch/x86/kvm/lapic.c +@@ -294,8 +294,16 @@ void kvm_apic_set_version(struct kvm_vcpu *vcpu) + if (!lapic_in_kernel(vcpu)) + return; + ++ /* ++ * KVM emulates 82093AA datasheet (with in-kernel IOAPIC implementation) ++ * which doesn't have EOI register; Some buggy OSes (e.g. Windows with ++ * Hyper-V role) disable EOI broadcast in lapic not checking for IOAPIC ++ * version first and level-triggered interrupts never get EOIed in ++ * IOAPIC. ++ */ + feat = kvm_find_cpuid_entry(apic->vcpu, 0x1, 0); +- if (feat && (feat->ecx & (1 << (X86_FEATURE_X2APIC & 31)))) ++ if (feat && (feat->ecx & (1 << (X86_FEATURE_X2APIC & 31))) && ++ !ioapic_in_kernel(vcpu->kvm)) + v |= APIC_LVR_DIRECTED_EOI; + kvm_lapic_set_reg(apic, APIC_LVR, v); + } +-- +2.7.4 + |