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Re: [Qemu-devel] [PATCH] kvm/irqchip: use bitmap utility for gsi trackin
From: |
Wei Yang |
Subject: |
Re: [Qemu-devel] [PATCH] kvm/irqchip: use bitmap utility for gsi tracking |
Date: |
Mon, 7 Mar 2016 13:53:31 +0000 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Mon, Mar 07, 2016 at 10:47:53AM +0100, Paolo Bonzini wrote:
>On 06/03/2016 02:57, Wei Yang wrote:
>> By using utilities in bitops and bitmap, this patch tries to make it more
>> friendly to audience. No functional change.
>>
>> Signed-off-by: Wei Yang <address@hidden>
>> ---
>> kvm-all.c | 34 ++++++++++------------------------
>> 1 file changed, 10 insertions(+), 24 deletions(-)
>>
>> diff --git a/kvm-all.c b/kvm-all.c
>> index bd9e764..ed3f4a2 100644
>> --- a/kvm-all.c
>> +++ b/kvm-all.c
>> @@ -90,7 +90,7 @@ struct KVMState
>> #ifdef KVM_CAP_IRQ_ROUTING
>> struct kvm_irq_routing *irq_routes;
>> int nr_allocated_irq_routes;
>> - uint32_t *used_gsi_bitmap;
>> + unsigned long *used_gsi_bitmap;
>> unsigned int gsi_count;
>> QTAILQ_HEAD(msi_hashtab, KVMMSIRoute) msi_hashtab[KVM_MSI_HASHTAB_SIZE];
>> #endif
>> @@ -951,12 +951,12 @@ typedef struct KVMMSIRoute {
>>
>> static void set_gsi(KVMState *s, unsigned int gsi)
>> {
>> - s->used_gsi_bitmap[gsi / 32] |= 1U << (gsi % 32);
>> + set_bit(gsi, s->used_gsi_bitmap);
>> }
>>
>> static void clear_gsi(KVMState *s, unsigned int gsi)
>> {
>> - s->used_gsi_bitmap[gsi / 32] &= ~(1U << (gsi % 32));
>> + clear_bit(gsi, s->used_gsi_bitmap);
>> }
>>
>> void kvm_init_irq_routing(KVMState *s)
>> @@ -965,17 +965,9 @@ void kvm_init_irq_routing(KVMState *s)
>>
>> gsi_count = kvm_check_extension(s, KVM_CAP_IRQ_ROUTING) - 1;
>> if (gsi_count > 0) {
>> - unsigned int gsi_bits, i;
>> -
>> /* Round up so we can search ints using ffs */
>> - gsi_bits = ALIGN(gsi_count, 32);
>> - s->used_gsi_bitmap = g_malloc0(gsi_bits / 8);
>> + s->used_gsi_bitmap = bitmap_new(gsi_count);
>> s->gsi_count = gsi_count;
>> -
>> - /* Mark any over-allocated bits as already in use */
>> - for (i = gsi_count; i < gsi_bits; i++) {
>> - set_gsi(s, i);
>> - }
>> }
>>
>> s->irq_routes = g_malloc0(sizeof(*s->irq_routes));
>> @@ -1105,9 +1097,7 @@ static void kvm_flush_dynamic_msi_routes(KVMState *s)
>>
>> static int kvm_irqchip_get_virq(KVMState *s)
>> {
>> - uint32_t *word = s->used_gsi_bitmap;
>> - int max_words = ALIGN(s->gsi_count, 32) / 32;
>> - int i, zeroes;
>> + int next_virq;
>>
>> /*
>> * PIC and IOAPIC share the first 16 GSI numbers, thus the available
>> @@ -1120,16 +1110,12 @@ static int kvm_irqchip_get_virq(KVMState *s)
>> }
>>
>> /* Return the lowest unused GSI in the bitmap */
>> - for (i = 0; i < max_words; i++) {
>> - zeroes = ctz32(~word[i]);
>> - if (zeroes == 32) {
>> - continue;
>> - }
>> -
>> - return zeroes + i * 32;
>> + next_virq = find_first_zero_bit(s->used_gsi_bitmap, s->gsi_count);
>> + if (next_virq >= s->gsi_count) {
>> + return -ENOSPC;
>> + } else {
>> + return next_virq;
>> }
>> - return -ENOSPC;
>> -
>> }
>>
>> static KVMMSIRoute *kvm_lookup_msi_route(KVMState *s, MSIMessage msg)
>>
>
>Queued, thanks. I will send a pull request today.
>
Thanks, glad to contribute :-)
>Paolo
--
Wei Yang
Help you, Help me