[v4] kvm: Use a bitmap for tracking used GSIs

Message ID	20090513043835.6696.27384.stgit@dl380g6-3.ned.telco.ned.telco (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n4D4fTtG025082 for <patchwork-kvm@patchwork.kernel.org>; Wed, 13 May 2009 04:41:30 GMT From: Alex Williamson <alex.williamson@hp.com> Subject: [PATCH v4] kvm: Use a bitmap for tracking used GSIs To: kvm@vger.kernel.org, sheng.yang@intel.com, mst@redhat.com Cc: alex.williamson@hp.com Date: Tue, 12 May 2009 22:41:29 -0600 Message-ID: <20090513043835.6696.27384.stgit@dl380g6-3.ned.telco.ned.telco> In-Reply-To: <20090512220142.5663.72948.stgit@dl380g6-3.ned.telco.ned.telco> References: <20090512220142.5663.72948.stgit@dl380g6-3.ned.telco.ned.telco> User-Agent: StGIT/0.14.2 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/hw/device-assignment.c b/hw/device-assignment.c index a7365c8..a6cc9b9 100644 --- a/hw/device-assignment.c +++ b/hw/device-assignment.c @@ -561,8 +561,10 @@ static void free_dev_irq_entries(AssignedDevice *dev) { int i; - for (i = 0; i < dev->irq_entries_nr; i++) + for (i = 0; i < dev->irq_entries_nr; i++) { kvm_del_routing_entry(kvm_context, &dev->entry[i]); + kvm_free_irq_route_gsi(kvm_context, dev->entry[i].gsi); + } free(dev->entry); dev->entry = NULL; dev->irq_entries_nr = 0; diff --git a/kvm/libkvm/kvm-common.h b/kvm/libkvm/kvm-common.h index 591fb53..4b3cb51 100644 --- a/kvm/libkvm/kvm-common.h +++ b/kvm/libkvm/kvm-common.h @@ -66,8 +66,10 @@ struct kvm_context { #ifdef KVM_CAP_IRQ_ROUTING struct kvm_irq_routing *irq_routes; int nr_allocated_irq_routes; + void *used_gsi_bitmap; + int max_gsi; + pthread_mutex_t gsi_mutex; #endif - int max_used_gsi; }; int kvm_alloc_kernel_memory(kvm_context_t kvm, unsigned long memory, diff --git a/kvm/libkvm/libkvm.c b/kvm/libkvm/libkvm.c index ba0a5d1..3eaa120 100644 --- a/kvm/libkvm/libkvm.c +++ b/kvm/libkvm/libkvm.c @@ -35,6 +35,7 @@ #include <errno.h> #include <sys/ioctl.h> #include <inttypes.h> +#include <pthread.h> #include "libkvm.h" #if defined(__x86_64__) || defined(__i386__) @@ -65,6 +66,8 @@ int kvm_abi = EXPECTED_KVM_API_VERSION; int kvm_page_size; +static inline void set_bit(uint32_t *buf, unsigned int bit); + struct slot_info { unsigned long phys_addr; unsigned long len; @@ -286,6 +289,9 @@ kvm_context_t kvm_init(struct kvm_callbacks *callbacks, int fd; kvm_context_t kvm; int r; +#ifdef KVM_CAP_IRQ_ROUTING + int gsi_count, gsi_bytes, i; +#endif fd = open("/dev/kvm", O_RDWR); if (fd == -1) { @@ -322,6 +328,25 @@ kvm_context_t kvm_init(struct kvm_callbacks *callbacks, kvm->dirty_pages_log_all = 0; kvm->no_irqchip_creation = 0; kvm->no_pit_creation = 0; +#ifdef KVM_CAP_IRQ_ROUTING + pthread_mutex_init(&kvm->gsi_mutex, NULL); + + gsi_count = kvm_get_gsi_count(kvm); + /* Round up so we can search ints using ffs */ + gsi_bytes = ((gsi_count + 31) / 32) * 4; + kvm->used_gsi_bitmap = malloc(gsi_bytes); + if (!kvm->used_gsi_bitmap) + goto out_close; + memset(kvm->used_gsi_bitmap, 0, gsi_bytes); + kvm->max_gsi = gsi_bytes * 8; + + /* Mark all the IOAPIC pin GSIs and any over-allocated + * GSIs as already in use. */ + for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++) + set_bit(kvm->used_gsi_bitmap, i); + for (i = gsi_count; i < kvm->max_gsi; i++) + set_bit(kvm->used_gsi_bitmap, i); +#endif return kvm; out_close: @@ -1298,8 +1323,6 @@ int kvm_add_routing_entry(kvm_context_t kvm, new->flags = entry->flags; new->u = entry->u; - if (entry->gsi > kvm->max_used_gsi) - kvm->max_used_gsi = entry->gsi; return 0; #else return -ENOSYS; @@ -1404,18 +1427,54 @@ int kvm_commit_irq_routes(kvm_context_t kvm) #endif } +#ifdef KVM_CAP_IRQ_ROUTING +static inline void set_bit(uint32_t *buf, unsigned int bit) +{ + buf[bit / 32] |= 1U << (bit % 32); +} + +static inline void clear_bit(uint32_t *buf, unsigned int bit) +{ + buf[bit / 32] &= ~(1U << (bit % 32)); +} + +static int kvm_find_free_gsi(kvm_context_t kvm) +{ + int i, bit, gsi; + uint32_t *buf = kvm->used_gsi_bitmap; + + for (i = 0; i < kvm->max_gsi / 32; i++) { + bit = ffs(~buf[i]); + if (!bit) + continue; + + gsi = bit - 1 + i * 32; + set_bit(buf, gsi); + return gsi; + } + + return -ENOSPC; +} +#endif + int kvm_get_irq_route_gsi(kvm_context_t kvm) { + int gsi = -ENOSYS; + #ifdef KVM_CAP_IRQ_ROUTING - if (kvm->max_used_gsi >= KVM_IOAPIC_NUM_PINS) { - if (kvm->max_used_gsi <= kvm_get_gsi_count(kvm)) - return kvm->max_used_gsi + 1; - else - return -ENOSPC; - } else - return KVM_IOAPIC_NUM_PINS; -#else - return -ENOSYS; + pthread_mutex_lock(&kvm->gsi_mutex); + gsi = kvm_find_free_gsi(kvm); + pthread_mutex_unlock(&kvm->gsi_mutex); +#endif + return gsi; +} + +void kvm_free_irq_route_gsi(kvm_context_t kvm, int gsi) +{ +#ifdef KVM_CAP_IRQ_ROUTING + pthread_mutex_lock(&kvm->gsi_mutex); + clear_bit(kvm->used_gsi_bitmap, gsi); + pthread_mutex_unlock(&kvm->gsi_mutex); #endif } diff --git a/kvm/libkvm/libkvm.h b/kvm/libkvm/libkvm.h index 4821a1e..845bb8a 100644 --- a/kvm/libkvm/libkvm.h +++ b/kvm/libkvm/libkvm.h @@ -856,6 +856,16 @@ int kvm_commit_irq_routes(kvm_context_t kvm); */ int kvm_get_irq_route_gsi(kvm_context_t kvm); +/*! + * \brief Free used GSI number + * + * Free used GSI number acquired from kvm_get_irq_route_gsi() + * + * \param kvm Pointer to the current kvm_context + * \param gsi GSI number to free + */ +void kvm_free_irq_route_gsi(kvm_context_t kvm, int gsi); + #ifdef KVM_CAP_DEVICE_MSIX int kvm_assign_set_msix_nr(kvm_context_t kvm, struct kvm_assigned_msix_nr *msix_nr);

[v4] kvm: Use a bitmap for tracking used GSIs

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