Fixes for 4.9

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-4.9/kvm-s390-reduce-number-of-io-pins-to-1.patch b/queue-4.9/kvm-s390-reduce-number-of-io-pins-to-1.patch
new file mode 100644 (file)
index 0000000..c651fd0
--- /dev/null
+++ b/queue-4.9/kvm-s390-reduce-number-of-io-pins-to-1.patch
@@ -0,0 +1,73 @@
+From 8c5721b13bef1cbc61c3dce8fe814a47bd13bf07 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Wed, 17 Jun 2020 10:36:20 +0200
+Subject: KVM: s390: reduce number of IO pins to 1
+
+From: Christian Borntraeger <borntraeger@de.ibm.com>
+
+[ Upstream commit 774911290c589e98e3638e73b24b0a4d4530e97c ]
+
+The current number of KVM_IRQCHIP_NUM_PINS results in an order 3
+allocation (32kb) for each guest start/restart. This can result in OOM
+killer activity even with free swap when the memory is fragmented
+enough:
+
+kernel: qemu-system-s39 invoked oom-killer: gfp_mask=0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_COMP|__GFP_ZERO), order=3, oom_score_adj=0
+kernel: CPU: 1 PID: 357274 Comm: qemu-system-s39 Kdump: loaded Not tainted 5.4.0-29-generic #33-Ubuntu
+kernel: Hardware name: IBM 8562 T02 Z06 (LPAR)
+kernel: Call Trace:
+kernel: ([<00000001f848fe2a>] show_stack+0x7a/0xc0)
+kernel:  [<00000001f8d3437a>] dump_stack+0x8a/0xc0
+kernel:  [<00000001f8687032>] dump_header+0x62/0x258
+kernel:  [<00000001f8686122>] oom_kill_process+0x172/0x180
+kernel:  [<00000001f8686abe>] out_of_memory+0xee/0x580
+kernel:  [<00000001f86e66b8>] __alloc_pages_slowpath+0xd18/0xe90
+kernel:  [<00000001f86e6ad4>] __alloc_pages_nodemask+0x2a4/0x320
+kernel:  [<00000001f86b1ab4>] kmalloc_order+0x34/0xb0
+kernel:  [<00000001f86b1b62>] kmalloc_order_trace+0x32/0xe0
+kernel:  [<00000001f84bb806>] kvm_set_irq_routing+0xa6/0x2e0
+kernel:  [<00000001f84c99a4>] kvm_arch_vm_ioctl+0x544/0x9e0
+kernel:  [<00000001f84b8936>] kvm_vm_ioctl+0x396/0x760
+kernel:  [<00000001f875df66>] do_vfs_ioctl+0x376/0x690
+kernel:  [<00000001f875e304>] ksys_ioctl+0x84/0xb0
+kernel:  [<00000001f875e39a>] __s390x_sys_ioctl+0x2a/0x40
+kernel:  [<00000001f8d55424>] system_call+0xd8/0x2c8
+
+As far as I can tell s390x does not use the iopins as we bail our for
+anything other than KVM_IRQ_ROUTING_S390_ADAPTER and the chip/pin is
+only used for KVM_IRQ_ROUTING_IRQCHIP. So let us use a small number to
+reduce the memory footprint.
+
+Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
+Reviewed-by: Cornelia Huck <cohuck@redhat.com>
+Reviewed-by: David Hildenbrand <david@redhat.com>
+Link: https://lore.kernel.org/r/20200617083620.5409-1-borntraeger@de.ibm.com
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ arch/s390/include/asm/kvm_host.h | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
+index 5792590d0e7c4..0b3c26e6930d9 100644
+--- a/arch/s390/include/asm/kvm_host.h
++++ b/arch/s390/include/asm/kvm_host.h
+@@ -32,12 +32,12 @@
+ #define KVM_USER_MEM_SLOTS 32
+ 
+ /*
+- * These seem to be used for allocating ->chip in the routing table,
+- * which we don't use. 4096 is an out-of-thin-air value. If we need
+- * to look at ->chip later on, we'll need to revisit this.
++ * These seem to be used for allocating ->chip in the routing table, which we
++ * don't use. 1 is as small as we can get to reduce the needed memory. If we
++ * need to look at ->chip later on, we'll need to revisit this.
+  */
+ #define KVM_NR_IRQCHIPS 1
+-#define KVM_IRQCHIP_NUM_PINS 4096
++#define KVM_IRQCHIP_NUM_PINS 1
+ #define KVM_HALT_POLL_NS_DEFAULT 80000
+ 
+ /* s390-specific vcpu->requests bit members */
+-- 
+2.25.1
+

diff --git a/queue-4.9/series b/queue-4.9/series
new file mode 100644 (file)
index 0000000..6f2e982
--- /dev/null
+++ b/queue-4.9/series
@@ -0,0 +1 @@
+kvm-s390-reduce-number-of-io-pins-to-1.patch