Re: [PATCH v1 25/29] virtio-mem: Big Block Mode (BBM) memory hotplug
On 19.10.20 04:26, Wei Yang wrote:
> On Mon, Oct 12, 2020 at 02:53:19PM +0200, David Hildenbrand wrote:
>> Currently, we do not support device block sizes that exceed the Linux
>> memory block size. For example, having a device block size of 1 GiB (e.g.,
>> gigantic pages in the hypervisor) won't work with 128 MiB Linux memory
>> blocks.
>>
>> Let's implement Big Block Mode (BBM), whereby we add/remove at least
>> one Linux memory block at a time. With a 1 GiB device block size, a Big
>> Block (BB) will cover 8 Linux memory blocks.
>>
>> We'll keep registering the online_page_callback machinery, it will be used
>> for safe memory hotunplug in BBM next.
>>
>> Note: BBM is properly prepared for variable-sized Linux memory
>> blocks that we might see in the future. So we won't care how many Linux
>> memory blocks a big block actually spans, and how the memory notifier is
>> called.
>>
>> Cc: "Michael S. Tsirkin"
>> Cc: Jason Wang
>> Cc: Pankaj Gupta
>> Cc: Michal Hocko
>> Cc: Oscar Salvador
>> Cc: Wei Yang
>> Cc: Andrew Morton
>> Signed-off-by: David Hildenbrand
>> ---
>> drivers/virtio/virtio_mem.c | 484 ++--
>> 1 file changed, 402 insertions(+), 82 deletions(-)
>>
>> diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
>> index e68d0d99590c..4d396ef98a92 100644
>> --- a/drivers/virtio/virtio_mem.c
>> +++ b/drivers/virtio/virtio_mem.c
>> @@ -30,12 +30,18 @@ MODULE_PARM_DESC(unplug_online, "Try to unplug online
>> memory");
>> /*
>> * virtio-mem currently supports the following modes of operation:
>> *
>> - * * Sub Block Mode (SBM): A Linux memory block spans 1..X subblocks (SB).
>> The
>> + * * Sub Block Mode (SBM): A Linux memory block spans 2..X subblocks (SB).
>> The
>> * size of a Sub Block (SB) is determined based on the device block size,
>> the
>> * pageblock size, and the maximum allocation granularity of the buddy.
>> * Subblocks within a Linux memory block might either be plugged or
>> unplugged.
>> * Memory is added/removed to Linux MM in Linux memory block granularity.
>> *
>> + * * Big Block Mode (BBM): A Big Block (BB) spans 1..X Linux memory blocks.
>> + * Memory is added/removed to Linux MM in Big Block granularity.
>> + *
>> + * The mode is determined automatically based on the Linux memory block size
>> + * and the device block size.
>> + *
>> * User space / core MM (auto onlining) is responsible for onlining added
>> * Linux memory blocks - and for selecting a zone. Linux Memory Blocks are
>> * always onlined separately, and all memory within a Linux memory block is
>> @@ -61,6 +67,19 @@ enum virtio_mem_sbm_mb_state {
>> VIRTIO_MEM_SBM_MB_COUNT
>> };
>>
>> +/*
>> + * State of a Big Block (BB) in BBM, covering 1..X Linux memory blocks.
>> + */
>> +enum virtio_mem_bbm_bb_state {
>> +/* Unplugged, not added to Linux. Can be reused later. */
>> +VIRTIO_MEM_BBM_BB_UNUSED = 0,
>> +/* Plugged, not added to Linux. Error on add_memory(). */
>> +VIRTIO_MEM_BBM_BB_PLUGGED,
>> +/* Plugged and added to Linux. */
>> +VIRTIO_MEM_BBM_BB_ADDED,
>> +VIRTIO_MEM_BBM_BB_COUNT
>> +};
>> +
>> struct virtio_mem {
>> struct virtio_device *vdev;
>>
>> @@ -113,6 +132,9 @@ struct virtio_mem {
>> atomic64_t offline_size;
>> uint64_t offline_threshold;
>>
>> +/* If set, the driver is in SBM, otherwise in BBM. */
>> +bool in_sbm;
>> +
>> struct {
>> /* Id of the first memory block of this device. */
>> unsigned long first_mb_id;
>> @@ -151,9 +173,27 @@ struct virtio_mem {
>> unsigned long *sb_states;
>> } sbm;
>>
>> +struct {
>> +/* Id of the first big block of this device. */
>> +unsigned long first_bb_id;
>> +/* Id of the last usable big block of this device. */
>> +unsigned long last_usable_bb_id;
>> +/* Id of the next device bock to prepare when needed. */
>> +unsigned long next_bb_id;
>> +
>> +/* Summary of all big block states. */
>> +unsigned long bb_count[VIRTIO_MEM_BBM_BB_COUNT];
>> +
>> +/* One byte state per big block. See sbm.mb_states. */
>> +uint8_t *bb_states;
>> +
>> +/* The block size used for (un)plugged, adding/removing. */
>> +uint64_t bb_size;
>> +} bbm;
>> +
>> /*
>> - * Mutex that protects the sbm.mb_count, sbm.mb_states, and
>> - * sbm.sb_states.
>> + * Mutex that protects the sbm.mb_count, sbm.mb_states,
>> + * sbm.sb_states, bbm.bb_count, and bbm.bb_states
>> *
>> * When this lock is held the pointers can't change, ONLINE and
>> * OFFLINE blocks can't change the state and no subblocks will get
>> @@ -247,6 +287,24 @@ static unsigned long virtio_mem_mb_id_to_phys(unsigned
>> long mb_id)
>> return mb_id * memory_block_size_bytes();
>> }
>>
>> +/*
>> + * Calculate the big block id of a given address.
>> + */
>> +static
Re: [PATCH v1 25/29] virtio-mem: Big Block Mode (BBM) memory hotplug
On Mon, Oct 12, 2020 at 02:53:19PM +0200, David Hildenbrand wrote:
>Currently, we do not support device block sizes that exceed the Linux
>memory block size. For example, having a device block size of 1 GiB (e.g.,
>gigantic pages in the hypervisor) won't work with 128 MiB Linux memory
>blocks.
>
>Let's implement Big Block Mode (BBM), whereby we add/remove at least
>one Linux memory block at a time. With a 1 GiB device block size, a Big
>Block (BB) will cover 8 Linux memory blocks.
>
>We'll keep registering the online_page_callback machinery, it will be used
>for safe memory hotunplug in BBM next.
>
>Note: BBM is properly prepared for variable-sized Linux memory
>blocks that we might see in the future. So we won't care how many Linux
>memory blocks a big block actually spans, and how the memory notifier is
>called.
>
>Cc: "Michael S. Tsirkin"
>Cc: Jason Wang
>Cc: Pankaj Gupta
>Cc: Michal Hocko
>Cc: Oscar Salvador
>Cc: Wei Yang
>Cc: Andrew Morton
>Signed-off-by: David Hildenbrand
>---
> drivers/virtio/virtio_mem.c | 484 ++--
> 1 file changed, 402 insertions(+), 82 deletions(-)
>
>diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
>index e68d0d99590c..4d396ef98a92 100644
>--- a/drivers/virtio/virtio_mem.c
>+++ b/drivers/virtio/virtio_mem.c
>@@ -30,12 +30,18 @@ MODULE_PARM_DESC(unplug_online, "Try to unplug online
>memory");
> /*
> * virtio-mem currently supports the following modes of operation:
> *
>- * * Sub Block Mode (SBM): A Linux memory block spans 1..X subblocks (SB). The
>+ * * Sub Block Mode (SBM): A Linux memory block spans 2..X subblocks (SB). The
> * size of a Sub Block (SB) is determined based on the device block size,
> the
> * pageblock size, and the maximum allocation granularity of the buddy.
> * Subblocks within a Linux memory block might either be plugged or
> unplugged.
> * Memory is added/removed to Linux MM in Linux memory block granularity.
> *
>+ * * Big Block Mode (BBM): A Big Block (BB) spans 1..X Linux memory blocks.
>+ * Memory is added/removed to Linux MM in Big Block granularity.
>+ *
>+ * The mode is determined automatically based on the Linux memory block size
>+ * and the device block size.
>+ *
> * User space / core MM (auto onlining) is responsible for onlining added
> * Linux memory blocks - and for selecting a zone. Linux Memory Blocks are
> * always onlined separately, and all memory within a Linux memory block is
>@@ -61,6 +67,19 @@ enum virtio_mem_sbm_mb_state {
> VIRTIO_MEM_SBM_MB_COUNT
> };
>
>+/*
>+ * State of a Big Block (BB) in BBM, covering 1..X Linux memory blocks.
>+ */
>+enum virtio_mem_bbm_bb_state {
>+ /* Unplugged, not added to Linux. Can be reused later. */
>+ VIRTIO_MEM_BBM_BB_UNUSED = 0,
>+ /* Plugged, not added to Linux. Error on add_memory(). */
>+ VIRTIO_MEM_BBM_BB_PLUGGED,
>+ /* Plugged and added to Linux. */
>+ VIRTIO_MEM_BBM_BB_ADDED,
>+ VIRTIO_MEM_BBM_BB_COUNT
>+};
>+
> struct virtio_mem {
> struct virtio_device *vdev;
>
>@@ -113,6 +132,9 @@ struct virtio_mem {
> atomic64_t offline_size;
> uint64_t offline_threshold;
>
>+ /* If set, the driver is in SBM, otherwise in BBM. */
>+ bool in_sbm;
>+
> struct {
> /* Id of the first memory block of this device. */
> unsigned long first_mb_id;
>@@ -151,9 +173,27 @@ struct virtio_mem {
> unsigned long *sb_states;
> } sbm;
>
>+ struct {
>+ /* Id of the first big block of this device. */
>+ unsigned long first_bb_id;
>+ /* Id of the last usable big block of this device. */
>+ unsigned long last_usable_bb_id;
>+ /* Id of the next device bock to prepare when needed. */
>+ unsigned long next_bb_id;
>+
>+ /* Summary of all big block states. */
>+ unsigned long bb_count[VIRTIO_MEM_BBM_BB_COUNT];
>+
>+ /* One byte state per big block. See sbm.mb_states. */
>+ uint8_t *bb_states;
>+
>+ /* The block size used for (un)plugged, adding/removing. */
>+ uint64_t bb_size;
>+ } bbm;
>+
> /*
>- * Mutex that protects the sbm.mb_count, sbm.mb_states, and
>- * sbm.sb_states.
>+ * Mutex that protects the sbm.mb_count, sbm.mb_states,
>+ * sbm.sb_states, bbm.bb_count, and bbm.bb_states
>*
>* When this lock is held the pointers can't change, ONLINE and
>* OFFLINE blocks can't change the state and no subblocks will get
>@@ -247,6 +287,24 @@ static unsigned long virtio_mem_mb_id_to_phys(unsigned
>long mb_id)
> return mb_id * memory_block_size_bytes();
> }
>
>+/*
>+ * Calculate the big block id of a given address.
>+ */
>+static unsigned long virtio_mem_phys_to_bb_id(struct virtio_mem *vm,
>+uint64_t addr)
>+{
>+ return addr / vm->bbm.bb_size;
>+}
>+
>+/*
Re: [PATCH v1 25/29] virtio-mem: Big Block Mode (BBM) memory hotplug
On 16.10.20 11:38, Wei Yang wrote:
> On Mon, Oct 12, 2020 at 02:53:19PM +0200, David Hildenbrand wrote:
>> Currently, we do not support device block sizes that exceed the Linux
>> memory block size. For example, having a device block size of 1 GiB (e.g.,
>> gigantic pages in the hypervisor) won't work with 128 MiB Linux memory
>> blocks.
>>
>> Let's implement Big Block Mode (BBM), whereby we add/remove at least
>> one Linux memory block at a time. With a 1 GiB device block size, a Big
>> Block (BB) will cover 8 Linux memory blocks.
>>
>> We'll keep registering the online_page_callback machinery, it will be used
>> for safe memory hotunplug in BBM next.
>>
>> Note: BBM is properly prepared for variable-sized Linux memory
>> blocks that we might see in the future. So we won't care how many Linux
>> memory blocks a big block actually spans, and how the memory notifier is
>> called.
>>
>> Cc: "Michael S. Tsirkin"
>> Cc: Jason Wang
>> Cc: Pankaj Gupta
>> Cc: Michal Hocko
>> Cc: Oscar Salvador
>> Cc: Wei Yang
>> Cc: Andrew Morton
>> Signed-off-by: David Hildenbrand
>> ---
>> drivers/virtio/virtio_mem.c | 484 ++--
>> 1 file changed, 402 insertions(+), 82 deletions(-)
>>
>> diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
>> index e68d0d99590c..4d396ef98a92 100644
>> --- a/drivers/virtio/virtio_mem.c
>> +++ b/drivers/virtio/virtio_mem.c
>> @@ -30,12 +30,18 @@ MODULE_PARM_DESC(unplug_online, "Try to unplug online
>> memory");
>> /*
>> * virtio-mem currently supports the following modes of operation:
>> *
>> - * * Sub Block Mode (SBM): A Linux memory block spans 1..X subblocks (SB).
>> The
>> + * * Sub Block Mode (SBM): A Linux memory block spans 2..X subblocks (SB).
>> The
>> * size of a Sub Block (SB) is determined based on the device block size,
>> the
>> * pageblock size, and the maximum allocation granularity of the buddy.
>> * Subblocks within a Linux memory block might either be plugged or
>> unplugged.
>> * Memory is added/removed to Linux MM in Linux memory block granularity.
>> *
>> + * * Big Block Mode (BBM): A Big Block (BB) spans 1..X Linux memory blocks.
>> + * Memory is added/removed to Linux MM in Big Block granularity.
>> + *
>> + * The mode is determined automatically based on the Linux memory block size
>> + * and the device block size.
>> + *
>> * User space / core MM (auto onlining) is responsible for onlining added
>> * Linux memory blocks - and for selecting a zone. Linux Memory Blocks are
>> * always onlined separately, and all memory within a Linux memory block is
>> @@ -61,6 +67,19 @@ enum virtio_mem_sbm_mb_state {
>> VIRTIO_MEM_SBM_MB_COUNT
>> };
>>
>> +/*
>> + * State of a Big Block (BB) in BBM, covering 1..X Linux memory blocks.
>> + */
>> +enum virtio_mem_bbm_bb_state {
>> +/* Unplugged, not added to Linux. Can be reused later. */
>> +VIRTIO_MEM_BBM_BB_UNUSED = 0,
>> +/* Plugged, not added to Linux. Error on add_memory(). */
>> +VIRTIO_MEM_BBM_BB_PLUGGED,
>> +/* Plugged and added to Linux. */
>> +VIRTIO_MEM_BBM_BB_ADDED,
>> +VIRTIO_MEM_BBM_BB_COUNT
>> +};
>> +
>> struct virtio_mem {
>> struct virtio_device *vdev;
>>
>> @@ -113,6 +132,9 @@ struct virtio_mem {
>> atomic64_t offline_size;
>> uint64_t offline_threshold;
>>
>> +/* If set, the driver is in SBM, otherwise in BBM. */
>> +bool in_sbm;
>> +
>> struct {
>> /* Id of the first memory block of this device. */
>> unsigned long first_mb_id;
>> @@ -151,9 +173,27 @@ struct virtio_mem {
>> unsigned long *sb_states;
>> } sbm;
>>
>> +struct {
>> +/* Id of the first big block of this device. */
>> +unsigned long first_bb_id;
>> +/* Id of the last usable big block of this device. */
>> +unsigned long last_usable_bb_id;
>> +/* Id of the next device bock to prepare when needed. */
>> +unsigned long next_bb_id;
>> +
>> +/* Summary of all big block states. */
>> +unsigned long bb_count[VIRTIO_MEM_BBM_BB_COUNT];
>> +
>> +/* One byte state per big block. See sbm.mb_states. */
>> +uint8_t *bb_states;
>> +
>> +/* The block size used for (un)plugged, adding/removing. */
>> +uint64_t bb_size;
>> +} bbm;
>
> Can we use a union here?
As I had the same thought initially, it most probably makes sense :)
Thanks!
--
Thanks,
David / dhildenb
Re: [PATCH v1 25/29] virtio-mem: Big Block Mode (BBM) memory hotplug
On Mon, Oct 12, 2020 at 02:53:19PM +0200, David Hildenbrand wrote:
>Currently, we do not support device block sizes that exceed the Linux
>memory block size. For example, having a device block size of 1 GiB (e.g.,
>gigantic pages in the hypervisor) won't work with 128 MiB Linux memory
>blocks.
>
>Let's implement Big Block Mode (BBM), whereby we add/remove at least
>one Linux memory block at a time. With a 1 GiB device block size, a Big
>Block (BB) will cover 8 Linux memory blocks.
>
>We'll keep registering the online_page_callback machinery, it will be used
>for safe memory hotunplug in BBM next.
>
>Note: BBM is properly prepared for variable-sized Linux memory
>blocks that we might see in the future. So we won't care how many Linux
>memory blocks a big block actually spans, and how the memory notifier is
>called.
>
>Cc: "Michael S. Tsirkin"
>Cc: Jason Wang
>Cc: Pankaj Gupta
>Cc: Michal Hocko
>Cc: Oscar Salvador
>Cc: Wei Yang
>Cc: Andrew Morton
>Signed-off-by: David Hildenbrand
>---
> drivers/virtio/virtio_mem.c | 484 ++--
> 1 file changed, 402 insertions(+), 82 deletions(-)
>
>diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
>index e68d0d99590c..4d396ef98a92 100644
>--- a/drivers/virtio/virtio_mem.c
>+++ b/drivers/virtio/virtio_mem.c
>@@ -30,12 +30,18 @@ MODULE_PARM_DESC(unplug_online, "Try to unplug online
>memory");
> /*
> * virtio-mem currently supports the following modes of operation:
> *
>- * * Sub Block Mode (SBM): A Linux memory block spans 1..X subblocks (SB). The
>+ * * Sub Block Mode (SBM): A Linux memory block spans 2..X subblocks (SB). The
> * size of a Sub Block (SB) is determined based on the device block size,
> the
> * pageblock size, and the maximum allocation granularity of the buddy.
> * Subblocks within a Linux memory block might either be plugged or
> unplugged.
> * Memory is added/removed to Linux MM in Linux memory block granularity.
> *
>+ * * Big Block Mode (BBM): A Big Block (BB) spans 1..X Linux memory blocks.
>+ * Memory is added/removed to Linux MM in Big Block granularity.
>+ *
>+ * The mode is determined automatically based on the Linux memory block size
>+ * and the device block size.
>+ *
> * User space / core MM (auto onlining) is responsible for onlining added
> * Linux memory blocks - and for selecting a zone. Linux Memory Blocks are
> * always onlined separately, and all memory within a Linux memory block is
>@@ -61,6 +67,19 @@ enum virtio_mem_sbm_mb_state {
> VIRTIO_MEM_SBM_MB_COUNT
> };
>
>+/*
>+ * State of a Big Block (BB) in BBM, covering 1..X Linux memory blocks.
>+ */
>+enum virtio_mem_bbm_bb_state {
>+ /* Unplugged, not added to Linux. Can be reused later. */
>+ VIRTIO_MEM_BBM_BB_UNUSED = 0,
>+ /* Plugged, not added to Linux. Error on add_memory(). */
>+ VIRTIO_MEM_BBM_BB_PLUGGED,
>+ /* Plugged and added to Linux. */
>+ VIRTIO_MEM_BBM_BB_ADDED,
>+ VIRTIO_MEM_BBM_BB_COUNT
>+};
>+
> struct virtio_mem {
> struct virtio_device *vdev;
>
>@@ -113,6 +132,9 @@ struct virtio_mem {
> atomic64_t offline_size;
> uint64_t offline_threshold;
>
>+ /* If set, the driver is in SBM, otherwise in BBM. */
>+ bool in_sbm;
>+
> struct {
> /* Id of the first memory block of this device. */
> unsigned long first_mb_id;
>@@ -151,9 +173,27 @@ struct virtio_mem {
> unsigned long *sb_states;
> } sbm;
>
>+ struct {
>+ /* Id of the first big block of this device. */
>+ unsigned long first_bb_id;
>+ /* Id of the last usable big block of this device. */
>+ unsigned long last_usable_bb_id;
>+ /* Id of the next device bock to prepare when needed. */
>+ unsigned long next_bb_id;
>+
>+ /* Summary of all big block states. */
>+ unsigned long bb_count[VIRTIO_MEM_BBM_BB_COUNT];
>+
>+ /* One byte state per big block. See sbm.mb_states. */
>+ uint8_t *bb_states;
>+
>+ /* The block size used for (un)plugged, adding/removing. */
>+ uint64_t bb_size;
>+ } bbm;
Can we use a union here?
>+
> /*
>- * Mutex that protects the sbm.mb_count, sbm.mb_states, and
>- * sbm.sb_states.
>+ * Mutex that protects the sbm.mb_count, sbm.mb_states,
>+ * sbm.sb_states, bbm.bb_count, and bbm.bb_states
>*
>* When this lock is held the pointers can't change, ONLINE and
>* OFFLINE blocks can't change the state and no subblocks will get
>@@ -247,6 +287,24 @@ static unsigned long virtio_mem_mb_id_to_phys(unsigned
>long mb_id)
> return mb_id * memory_block_size_bytes();
> }
>
>+/*
>+ * Calculate the big block id of a given address.
>+ */
>+static unsigned long virtio_mem_phys_to_bb_id(struct virtio_mem *vm,
>+uint64_t addr)
>+{
>+ return addr /
[PATCH v1 25/29] virtio-mem: Big Block Mode (BBM) memory hotplug
Currently, we do not support device block sizes that exceed the Linux
memory block size. For example, having a device block size of 1 GiB (e.g.,
gigantic pages in the hypervisor) won't work with 128 MiB Linux memory
blocks.
Let's implement Big Block Mode (BBM), whereby we add/remove at least
one Linux memory block at a time. With a 1 GiB device block size, a Big
Block (BB) will cover 8 Linux memory blocks.
We'll keep registering the online_page_callback machinery, it will be used
for safe memory hotunplug in BBM next.
Note: BBM is properly prepared for variable-sized Linux memory
blocks that we might see in the future. So we won't care how many Linux
memory blocks a big block actually spans, and how the memory notifier is
called.
Cc: "Michael S. Tsirkin"
Cc: Jason Wang
Cc: Pankaj Gupta
Cc: Michal Hocko
Cc: Oscar Salvador
Cc: Wei Yang
Cc: Andrew Morton
Signed-off-by: David Hildenbrand
---
drivers/virtio/virtio_mem.c | 484 ++--
1 file changed, 402 insertions(+), 82 deletions(-)
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index e68d0d99590c..4d396ef98a92 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -30,12 +30,18 @@ MODULE_PARM_DESC(unplug_online, "Try to unplug online
memory");
/*
* virtio-mem currently supports the following modes of operation:
*
- * * Sub Block Mode (SBM): A Linux memory block spans 1..X subblocks (SB). The
+ * * Sub Block Mode (SBM): A Linux memory block spans 2..X subblocks (SB). The
* size of a Sub Block (SB) is determined based on the device block size, the
* pageblock size, and the maximum allocation granularity of the buddy.
* Subblocks within a Linux memory block might either be plugged or
unplugged.
* Memory is added/removed to Linux MM in Linux memory block granularity.
*
+ * * Big Block Mode (BBM): A Big Block (BB) spans 1..X Linux memory blocks.
+ * Memory is added/removed to Linux MM in Big Block granularity.
+ *
+ * The mode is determined automatically based on the Linux memory block size
+ * and the device block size.
+ *
* User space / core MM (auto onlining) is responsible for onlining added
* Linux memory blocks - and for selecting a zone. Linux Memory Blocks are
* always onlined separately, and all memory within a Linux memory block is
@@ -61,6 +67,19 @@ enum virtio_mem_sbm_mb_state {
VIRTIO_MEM_SBM_MB_COUNT
};
+/*
+ * State of a Big Block (BB) in BBM, covering 1..X Linux memory blocks.
+ */
+enum virtio_mem_bbm_bb_state {
+ /* Unplugged, not added to Linux. Can be reused later. */
+ VIRTIO_MEM_BBM_BB_UNUSED = 0,
+ /* Plugged, not added to Linux. Error on add_memory(). */
+ VIRTIO_MEM_BBM_BB_PLUGGED,
+ /* Plugged and added to Linux. */
+ VIRTIO_MEM_BBM_BB_ADDED,
+ VIRTIO_MEM_BBM_BB_COUNT
+};
+
struct virtio_mem {
struct virtio_device *vdev;
@@ -113,6 +132,9 @@ struct virtio_mem {
atomic64_t offline_size;
uint64_t offline_threshold;
+ /* If set, the driver is in SBM, otherwise in BBM. */
+ bool in_sbm;
+
struct {
/* Id of the first memory block of this device. */
unsigned long first_mb_id;
@@ -151,9 +173,27 @@ struct virtio_mem {
unsigned long *sb_states;
} sbm;
+ struct {
+ /* Id of the first big block of this device. */
+ unsigned long first_bb_id;
+ /* Id of the last usable big block of this device. */
+ unsigned long last_usable_bb_id;
+ /* Id of the next device bock to prepare when needed. */
+ unsigned long next_bb_id;
+
+ /* Summary of all big block states. */
+ unsigned long bb_count[VIRTIO_MEM_BBM_BB_COUNT];
+
+ /* One byte state per big block. See sbm.mb_states. */
+ uint8_t *bb_states;
+
+ /* The block size used for (un)plugged, adding/removing. */
+ uint64_t bb_size;
+ } bbm;
+
/*
-* Mutex that protects the sbm.mb_count, sbm.mb_states, and
-* sbm.sb_states.
+* Mutex that protects the sbm.mb_count, sbm.mb_states,
+* sbm.sb_states, bbm.bb_count, and bbm.bb_states
*
* When this lock is held the pointers can't change, ONLINE and
* OFFLINE blocks can't change the state and no subblocks will get
@@ -247,6 +287,24 @@ static unsigned long virtio_mem_mb_id_to_phys(unsigned
long mb_id)
return mb_id * memory_block_size_bytes();
}
+/*
+ * Calculate the big block id of a given address.
+ */
+static unsigned long virtio_mem_phys_to_bb_id(struct virtio_mem *vm,
+ uint64_t addr)
+{
+ return addr / vm->bbm.bb_size;
+}
+
+/*
+ * Calculate the physical start address of a given big block id.
+ */
+static uint64_t virtio_mem_bb_id_to_phys(struct virtio_mem *vm,
+
