vhost: add max_mem_regions module parameter (c9ce42f7) · Commits · 戴 / test

it became possible to use a bigger amount of memory slots, which is used by memory hotplug for registering hotplugged memory. However QEMU crashes if it's used with more than ~60 pc-dimm devices and vhost-net enabled since host kernel in module vhost-net refuses to accept more than 64 memory regions. Allow to tweak limit via max_mem_regions module paramemter with default value set to 64 slots. Signed-off-by:

Igor Mammedov <imammedo@redhat.com> Signed-off-by:

Michael S. Tsirkin <mst@redhat.com>

drivers/vhost/vhost.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -30,8 +30,12 @@

		#include "vhost.h"

		static ushort max_mem_regions = 64;
		module_param(max_mem_regions, ushort, 0444);
		MODULE_PARM_DESC(max_mem_regions,
		"Maximum number of memory regions in memory map. (default: 64)");

		enum {
		VHOST_MEMORY_MAX_NREGIONS = 64,
		VHOST_MEMORY_F_LOG = 0x1,
		};

		@@ -697,7 +701,7 @@ static long vhost_set_memory(struct vhost_dev d, struct vhost_memory __user m)
		return -EFAULT;
		if (mem.padding)
		return -EOPNOTSUPP;
		if (mem.nregions > VHOST_MEMORY_MAX_NREGIONS)
		if (mem.nregions > max_mem_regions)
		return -E2BIG;
		newmem = vhost_kvzalloc(size + mem.nregions * sizeof(*m->regions));
		if (!newmem)

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