Adding debian version 4.19.249-2.debian/4.19.249-2debian

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/debian/patches-rt/0049-powerpc-kvm-Disable-in-kernel-MPIC-emulation-for-PRE.patch b/debian/patches-rt/0049-powerpc-kvm-Disable-in-kernel-MPIC-emulation-for-PRE.patch
new file mode 100644
index 000000000..f019d3e49
--- /dev/null
+++ b/debian/patches-rt/0049-powerpc-kvm-Disable-in-kernel-MPIC-emulation-for-PRE.patch
@@ -0,0 +1,45 @@
+From d20454871d553f909f09445def1ccc5edee641de Mon Sep 17 00:00:00 2001
+From: Bogdan Purcareata <bogdan.purcareata@freescale.com>
+Date: Fri, 24 Apr 2015 15:53:13 +0000
+Subject: [PATCH 049/347] powerpc/kvm: Disable in-kernel MPIC emulation for
+ PREEMPT_RT_FULL
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
+
+While converting the openpic emulation code to use a raw_spinlock_t enables
+guests to run on RT, there's still a performance issue. For interrupts sent in
+directed delivery mode with a multiple CPU mask, the emulated openpic will loop
+through all of the VCPUs, and for each VCPUs, it call IRQ_check, which will loop
+through all the pending interrupts for that VCPU. This is done while holding the
+raw_lock, meaning that in all this time the interrupts and preemption are
+disabled on the host Linux. A malicious user app can max both these number and
+cause a DoS.
+
+This temporary fix is sent for two reasons. First is so that users who want to
+use the in-kernel MPIC emulation are aware of the potential latencies, thus
+making sure that the hardware MPIC and their usage scenario does not involve
+interrupts sent in directed delivery mode, and the number of possible pending
+interrupts is kept small. Secondly, this should incentivize the development of a
+proper openpic emulation that would be better suited for RT.
+
+Acked-by: Scott Wood <scottwood@freescale.com>
+Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ arch/powerpc/kvm/Kconfig | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
+index 68a0e9d5b440..6f4d5d7615af 100644
+--- a/arch/powerpc/kvm/Kconfig
++++ b/arch/powerpc/kvm/Kconfig
+@@ -178,6 +178,7 @@ config KVM_E500MC
+ config KVM_MPIC
+ 	bool "KVM in-kernel MPIC emulation"
+ 	depends on KVM && E500
++	depends on !PREEMPT_RT_FULL
+ 	select HAVE_KVM_IRQCHIP
+ 	select HAVE_KVM_IRQFD
+ 	select HAVE_KVM_IRQ_ROUTING
+-- 
+2.36.1
+