| Message ID | 1386598213-8156-3-git-send-email-akong@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 12/09/2013 07:10 AM, Amos Kong wrote: > This patch makes the buffer size configurable, the max > buffer size is 65536. > > -object rng-egd,chardev=chr0,id=rng0,buf_size=1024 > > Signed-off-by: Amos Kong <akong@redhat.com> > --- > backends/rng-egd.c | 24 +++++++++++++++++++++--- > 1 file changed, 21 insertions(+), 3 deletions(-) > @@ -281,6 +298,7 @@ static void rng_egd_init(Object *obj) > object_property_add_str(obj, "chardev", > rng_egd_get_chardev, rng_egd_set_chardev, > NULL); > + object_property_add_str(obj, "buf_size", NULL, rng_egd_set_buf_size, NULL); > } Will libvirt ever need to set this property? And is it easily discoverable whether qemu supports or lacks this property?
On Tue, Dec 10, 2013 at 09:58:19AM -0700, Eric Blake wrote: > On 12/09/2013 07:10 AM, Amos Kong wrote: Hi Eric, > > This patch makes the buffer size configurable, the max > > buffer size is 65536. > > > > -object rng-egd,chardev=chr0,id=rng0,buf_size=1024 > > > > Signed-off-by: Amos Kong <akong@redhat.com> > > --- > > backends/rng-egd.c | 24 +++++++++++++++++++++--- > > 1 file changed, 21 insertions(+), 3 deletions(-) > > > @@ -281,6 +298,7 @@ static void rng_egd_init(Object *obj) > > object_property_add_str(obj, "chardev", > > rng_egd_get_chardev, rng_egd_set_chardev, > > NULL); > > + object_property_add_str(obj, "buf_size", NULL, rng_egd_set_buf_size, NULL); > > } > > Will libvirt ever need to set this property? And is it easily > discoverable whether qemu supports or lacks this property? This is ajust a RFC patch, we might fix the performance with other method. If it won't cost too much memory for buf, we can remove this parameter. In this patch, we have a default buffer size. > -- > Eric Blake eblake redhat com +1-919-301-3266 > Libvirt virtualization library http://libvirt.org
diff --git a/backends/rng-egd.c b/backends/rng-egd.c index d317c61..4e5ba18 100644 --- a/backends/rng-egd.c +++ b/backends/rng-egd.c @@ -18,7 +18,7 @@ #define TYPE_RNG_EGD "rng-egd" #define RNG_EGD(obj) OBJECT_CHECK(RngEgd, (obj), TYPE_RNG_EGD) -#define BUFFER_SIZE 65536 +#define MAX_BUFFER_SIZE 65536 typedef struct RngEgd { @@ -31,6 +31,7 @@ typedef struct RngEgd GSList *requests; void *opaque; size_t req_size; + uint32_t buf_size; } RngEgd; typedef struct RngRequest @@ -154,9 +155,16 @@ static void rng_egd_request_entropy(RngBackend *b, size_t size, } int total_size = get_total_buf_size(s); + int buf_size; - while (total_size < BUFFER_SIZE) { - int add_size = MIN(BUFFER_SIZE - total_size, 255); + if (s->buf_size != 0) { + buf_size = MIN(s->buf_size, MAX_BUFFER_SIZE); + } else { + buf_size = MAX_BUFFER_SIZE; + } + + while (total_size < buf_size) { + int add_size = MIN(buf_size - total_size, 255); total_size += add_size; rng_egd_append_request(b, add_size, receive_entropy, opaque); } @@ -253,6 +261,15 @@ static void rng_egd_opened(RngBackend *b, Error **errp) NULL, s); } +static void rng_egd_set_buf_size(Object *obj, const char *value, Error **errp) +{ + RngBackend *b = RNG_BACKEND(obj); + RngEgd *s = RNG_EGD(b); + + s->buf_size = atoi(value); + assert(s->buf_size > 0); +} + static void rng_egd_set_chardev(Object *obj, const char *value, Error **errp) { RngBackend *b = RNG_BACKEND(obj); @@ -281,6 +298,7 @@ static void rng_egd_init(Object *obj) object_property_add_str(obj, "chardev", rng_egd_get_chardev, rng_egd_set_chardev, NULL); + object_property_add_str(obj, "buf_size", NULL, rng_egd_set_buf_size, NULL); } static void rng_egd_finalize(Object *obj)
This patch makes the buffer size configurable, the max buffer size is 65536. -object rng-egd,chardev=chr0,id=rng0,buf_size=1024 Signed-off-by: Amos Kong <akong@redhat.com> --- backends/rng-egd.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)