On Thu, 5 Oct 2023, Vikram Garhwal wrote:
> From: Juergen Gross <jgr...@suse.com>
>
> Add a memory region which can be used to automatically map granted
> memory. It is starting at 0x8000000000000000ULL in order to be able to
> distinguish it from normal RAM.
>
> For this reason the xen.ram memory region is expanded, which has no
> further impact as it is used just as a container of the real RAM
> regions and now the grant region.
>
> Signed-off-by: Juergen Gross <jgr...@suse.com>
> Signed-off-by: Vikram Garhwal <vikram.garh...@amd.com>
This patch doesn't apply to staging anymore
> ---
> hw/i386/xen/xen-hvm.c | 3 ++
> hw/xen/xen-hvm-common.c | 4 +--
> hw/xen/xen-mapcache.c | 27 ++++++++++++++
> include/exec/ram_addr.h | 1 +
> include/hw/xen/xen-hvm-common.h | 2 ++
> include/hw/xen/xen_pvdev.h | 3 ++
> include/sysemu/xen-mapcache.h | 3 ++
> softmmu/physmem.c | 62 +++++++++++++++++++++------------
> 8 files changed, 80 insertions(+), 25 deletions(-)
>
> diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c
> index f42621e674..67a55558a6 100644
> --- a/hw/i386/xen/xen-hvm.c
> +++ b/hw/i386/xen/xen-hvm.c
> @@ -172,6 +172,9 @@ static void xen_ram_init(PCMachineState *pcms,
> x86ms->above_4g_mem_size);
> memory_region_add_subregion(sysmem, 0x100000000ULL, &ram_hi);
> }
> +
> + /* Add grant mappings as a pseudo RAM region. */
> + ram_grants = *xen_init_grant_ram();
> }
>
> static XenPhysmap *get_physmapping(hwaddr start_addr, ram_addr_t size)
> diff --git a/hw/xen/xen-hvm-common.c b/hw/xen/xen-hvm-common.c
> index 565dc39c8f..b7255977a5 100644
> --- a/hw/xen/xen-hvm-common.c
> +++ b/hw/xen/xen-hvm-common.c
> @@ -9,7 +9,7 @@
> #include "hw/boards.h"
> #include "hw/xen/arch_hvm.h"
>
> -MemoryRegion ram_memory;
> +MemoryRegion ram_memory, ram_grants;
>
> void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size, MemoryRegion *mr,
> Error **errp)
> @@ -26,7 +26,7 @@ void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
> MemoryRegion *mr,
> return;
> }
>
> - if (mr == &ram_memory) {
> + if (mr == &ram_memory || mr == &ram_grants) {
> return;
> }
>
> diff --git a/hw/xen/xen-mapcache.c b/hw/xen/xen-mapcache.c
> index f7d974677d..8115c44c00 100644
> --- a/hw/xen/xen-mapcache.c
> +++ b/hw/xen/xen-mapcache.c
> @@ -14,7 +14,9 @@
>
> #include <sys/resource.h>
>
> +#include "hw/xen/xen-hvm-common.h"
> #include "hw/xen/xen_native.h"
> +#include "hw/xen/xen_pvdev.h"
> #include "qemu/bitmap.h"
>
> #include "sysemu/runstate.h"
> @@ -597,3 +599,28 @@ uint8_t *xen_replace_cache_entry(hwaddr old_phys_addr,
> mapcache_unlock();
> return p;
> }
> +
> +MemoryRegion *xen_init_grant_ram(void)
> +{
> + RAMBlock *block;
> +
> + memory_region_init(&ram_grants, NULL, "xen.grants",
> + XEN_MAX_VIRTIO_GRANTS * XC_PAGE_SIZE);
> + block = g_malloc0(sizeof(*block));
> + block->mr = &ram_grants;
> + block->used_length = XEN_MAX_VIRTIO_GRANTS * XC_PAGE_SIZE;
> + block->max_length = XEN_MAX_VIRTIO_GRANTS * XC_PAGE_SIZE;
> + block->fd = -1;
> + block->page_size = XC_PAGE_SIZE;
> + block->host = (void *)XEN_GRANT_ADDR_OFF;
> + block->offset = XEN_GRANT_ADDR_OFF;
> + block->flags = RAM_PREALLOC;
> + ram_grants.ram_block = block;
> + ram_grants.ram = true;
> + ram_grants.terminates = true;
> + ram_block_add_list(block);
> + memory_region_add_subregion(get_system_memory(), XEN_GRANT_ADDR_OFF,
> + &ram_grants);
> +
> + return &ram_grants;
It doesn't look like xen_init_grant_ram has anything to do with the
mapcache. It should be in another file. Maybe ./hw/xen/xen-hvm-common.c
or ./hw/i386/xen/xen-hvm.c (but this is x86 specific and we need grants
on ARM too)
> +}
> diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
> index 90676093f5..c0b5f9a7d0 100644
> --- a/include/exec/ram_addr.h
> +++ b/include/exec/ram_addr.h
> @@ -139,6 +139,7 @@ void qemu_ram_free(RAMBlock *block);
> int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
>
> void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length);
> +void ram_block_add_list(RAMBlock *new_block);
>
> /* Clear whole block of mem */
> static inline void qemu_ram_block_writeback(RAMBlock *block)
> diff --git a/include/hw/xen/xen-hvm-common.h b/include/hw/xen/xen-hvm-common.h
> index 4e9904f1a6..0d300ba898 100644
> --- a/include/hw/xen/xen-hvm-common.h
> +++ b/include/hw/xen/xen-hvm-common.h
> @@ -17,6 +17,8 @@
> #include <xen/hvm/ioreq.h>
>
> extern MemoryRegion ram_memory;
> +
> +extern MemoryRegion ram_grants;
> extern MemoryListener xen_io_listener;
> extern DeviceListener xen_device_listener;
>
> diff --git a/include/hw/xen/xen_pvdev.h b/include/hw/xen/xen_pvdev.h
> index ddad4b9f36..0f1b5edfa9 100644
> --- a/include/hw/xen/xen_pvdev.h
> +++ b/include/hw/xen/xen_pvdev.h
> @@ -80,4 +80,7 @@ int xen_pv_send_notify(struct XenLegacyDevice *xendev);
> void xen_pv_printf(struct XenLegacyDevice *xendev, int msg_level,
> const char *fmt, ...) G_GNUC_PRINTF(3, 4);
>
> +#define XEN_GRANT_ADDR_OFF 0x8000000000000000ULL
> +#define XEN_MAX_VIRTIO_GRANTS 65536
> +
> #endif /* QEMU_HW_XEN_PVDEV_H */
> diff --git a/include/sysemu/xen-mapcache.h b/include/sysemu/xen-mapcache.h
> index c8e7c2f6cf..f4bedb1c11 100644
> --- a/include/sysemu/xen-mapcache.h
> +++ b/include/sysemu/xen-mapcache.h
> @@ -10,6 +10,7 @@
> #define XEN_MAPCACHE_H
>
> #include "exec/cpu-common.h"
> +#include "exec/ram_addr.h"
>
> typedef hwaddr (*phys_offset_to_gaddr_t)(hwaddr phys_offset,
> ram_addr_t size);
> @@ -25,6 +26,8 @@ void xen_invalidate_map_cache(void);
> uint8_t *xen_replace_cache_entry(hwaddr old_phys_addr,
> hwaddr new_phys_addr,
> hwaddr size);
> +MemoryRegion *xen_init_grant_ram(void);
> +
> #else
>
> static inline void xen_map_cache_init(phys_offset_to_gaddr_t f,
> diff --git a/softmmu/physmem.c b/softmmu/physmem.c
> index 309653c722..e182a2fa07 100644
> --- a/softmmu/physmem.c
> +++ b/softmmu/physmem.c
You might want to split this change out of this patch to make it easier
to get the physmem.c maintainers' attention
> @@ -1803,12 +1803,47 @@ static void dirty_memory_extend(ram_addr_t
> old_ram_size,
> }
> }
>
> +static void ram_block_add_list_locked(RAMBlock *new_block)
> + {
> + RAMBlock *block;
> + RAMBlock *last_block = NULL;
> +
> + /*
> + * Keep the list sorted from biggest to smallest block. Unlike QTAILQ,
> + * QLIST (which has an RCU-friendly variant) does not have insertion at
> + * tail, so save the last element in last_block.
> + */
> + RAMBLOCK_FOREACH(block) {
> + last_block = block;
> + if (block->max_length < new_block->max_length) {
> + break;
> + }
> + }
> + if (block) {
> + QLIST_INSERT_BEFORE_RCU(block, new_block, next);
> + } else if (last_block) {
> + QLIST_INSERT_AFTER_RCU(last_block, new_block, next);
> + } else { /* list is empty */
> + QLIST_INSERT_HEAD_RCU(&ram_list.blocks, new_block, next);
> + }
> + ram_list.mru_block = NULL;
> +
> + /* Write list before version */
> + smp_wmb();
> + ram_list.version++;
> +}
> +
> +void ram_block_add_list(RAMBlock *new_block)
> +{
> + qemu_mutex_lock_ramlist();
> + ram_block_add_list_locked(new_block);
> + qemu_mutex_unlock_ramlist();
> +}
> +
> static void ram_block_add(RAMBlock *new_block, Error **errp)
> {
> const bool noreserve = qemu_ram_is_noreserve(new_block);
> const bool shared = qemu_ram_is_shared(new_block);
> - RAMBlock *block;
> - RAMBlock *last_block = NULL;
> ram_addr_t old_ram_size, new_ram_size;
> Error *err = NULL;
>
> @@ -1846,28 +1881,9 @@ static void ram_block_add(RAMBlock *new_block, Error
> **errp)
> if (new_ram_size > old_ram_size) {
> dirty_memory_extend(old_ram_size, new_ram_size);
> }
> - /* Keep the list sorted from biggest to smallest block. Unlike QTAILQ,
> - * QLIST (which has an RCU-friendly variant) does not have insertion at
> - * tail, so save the last element in last_block.
> - */
> - RAMBLOCK_FOREACH(block) {
> - last_block = block;
> - if (block->max_length < new_block->max_length) {
> - break;
> - }
> - }
> - if (block) {
> - QLIST_INSERT_BEFORE_RCU(block, new_block, next);
> - } else if (last_block) {
> - QLIST_INSERT_AFTER_RCU(last_block, new_block, next);
> - } else { /* list is empty */
> - QLIST_INSERT_HEAD_RCU(&ram_list.blocks, new_block, next);
> - }
> - ram_list.mru_block = NULL;
>
> - /* Write list before version */
> - smp_wmb();
> - ram_list.version++;
> + ram_block_add_list_locked(new_block);
> +
> qemu_mutex_unlock_ramlist();
>
> cpu_physical_memory_set_dirty_range(new_block->offset,
> --
> 2.17.1
>
