9564e138b1
Changes since V3: - Do not do endian conversions as they will be done in the host - Report stats that reference a quantity of memory in bytes - Minor coding style updates Changes since V2: - Increase stat field size to 64 bits - Report all sizes in kb (not pages) - Drop anon_pages stat and fix endianness conversion Changes since V1: - Use a virtqueue instead of the device config space When using ballooning to manage overcommitted memory on a host, a system for guests to communicate their memory usage to the host can provide information that will minimize the impact of ballooning on the guests. The current method employs a daemon running in each guest that communicates memory statistics to a host daemon at a specified time interval. The host daemon aggregates this information and inflates and/or deflates balloons according to the level of host memory pressure. This approach is effective but overly complex since a daemon must be installed inside each guest and coordinated to communicate with the host. A simpler approach is to collect memory statistics in the virtio balloon driver and communicate them directly to the hypervisor. This patch enables the guest-side support by adding stats collection and reporting to the virtio balloon driver. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Anthony Liguori <anthony@codemonkey.ws> Cc: virtualization@lists.linux-foundation.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (minor fixes)
36 lines
1.2 KiB
C
36 lines
1.2 KiB
C
#ifndef _LINUX_VIRTIO_BALLOON_H
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#define _LINUX_VIRTIO_BALLOON_H
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/* This header is BSD licensed so anyone can use the definitions to implement
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* compatible drivers/servers. */
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#include <linux/virtio_ids.h>
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#include <linux/virtio_config.h>
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/* The feature bitmap for virtio balloon */
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#define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */
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#define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */
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/* Size of a PFN in the balloon interface. */
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#define VIRTIO_BALLOON_PFN_SHIFT 12
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struct virtio_balloon_config
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{
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/* Number of pages host wants Guest to give up. */
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__le32 num_pages;
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/* Number of pages we've actually got in balloon. */
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__le32 actual;
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};
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#define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */
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#define VIRTIO_BALLOON_S_SWAP_OUT 1 /* Amount of memory swapped out */
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#define VIRTIO_BALLOON_S_MAJFLT 2 /* Number of major faults */
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#define VIRTIO_BALLOON_S_MINFLT 3 /* Number of minor faults */
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#define VIRTIO_BALLOON_S_MEMFREE 4 /* Total amount of free memory */
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#define VIRTIO_BALLOON_S_MEMTOT 5 /* Total amount of memory */
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#define VIRTIO_BALLOON_S_NR 6
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struct virtio_balloon_stat {
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u16 tag;
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u64 val;
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} __attribute__((packed));
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#endif /* _LINUX_VIRTIO_BALLOON_H */
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