From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54524) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ThhkP-000087-Jr for qemu-devel@nongnu.org; Sun, 09 Dec 2012 09:20:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ThhkO-0004Km-8k for qemu-devel@nongnu.org; Sun, 09 Dec 2012 09:20:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:15929) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ThhkN-0004Ka-Pf for qemu-devel@nongnu.org; Sun, 09 Dec 2012 09:20:47 -0500 Date: Sun, 9 Dec 2012 16:20:43 +0200 From: Gleb Natapov Message-ID: <20121209142043.GB29003@redhat.com> References: <20121207194503.20524.17054.stgit@bling.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121207194503.20524.17054.stgit@bling.home> Subject: Re: [Qemu-devel] [PATCH] kvm: Detect number of available memory slots from the host kernel List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: mtosatti@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org On Fri, Dec 07, 2012 at 12:46:10PM -0700, Alex Williamson wrote: > The kernel already exposes an interface for this, x86 returns a proper > value and for the rest we can default to the defacto standard of 32. > The primary motivation for this is to support more PCI assigned > devices, both through pci-assign and vfio-pci. > > Signed-off-by: Alex Williamson > --- > kvm-all.c | 27 ++++++++++++++++++--------- > 1 file changed, 18 insertions(+), 9 deletions(-) > > diff --git a/kvm-all.c b/kvm-all.c > index 8e9a8d8..34d97f3 100644 > --- a/kvm-all.c > +++ b/kvm-all.c > @@ -71,7 +71,8 @@ typedef struct kvm_dirty_log KVMDirtyLog; > > struct KVMState > { > - KVMSlot slots[32]; > + KVMSlot *slots; > + int num_slots; > int fd; > int vmfd; > int coalesced_mmio; > @@ -120,7 +121,7 @@ static KVMSlot *kvm_alloc_slot(KVMState *s) > { > int i; > > - for (i = 0; i < ARRAY_SIZE(s->slots); i++) { > + for (i = 0; i < s->num_slots; i++) { > if (s->slots[i].memory_size == 0) { > return &s->slots[i]; > } > @@ -136,7 +137,7 @@ static KVMSlot *kvm_lookup_matching_slot(KVMState *s, > { > int i; > > - for (i = 0; i < ARRAY_SIZE(s->slots); i++) { > + for (i = 0; i < s->num_slots; i++) { > KVMSlot *mem = &s->slots[i]; > > if (start_addr == mem->start_addr && > @@ -158,7 +159,7 @@ static KVMSlot *kvm_lookup_overlapping_slot(KVMState *s, > KVMSlot *found = NULL; > int i; > > - for (i = 0; i < ARRAY_SIZE(s->slots); i++) { > + for (i = 0; i < s->num_slots; i++) { > KVMSlot *mem = &s->slots[i]; > > if (mem->memory_size == 0 || > @@ -180,7 +181,7 @@ int kvm_physical_memory_addr_from_host(KVMState *s, void *ram, > { > int i; > > - for (i = 0; i < ARRAY_SIZE(s->slots); i++) { > + for (i = 0; i < s->num_slots; i++) { > KVMSlot *mem = &s->slots[i]; > > if (ram >= mem->ram && ram < mem->ram + mem->memory_size) { > @@ -340,7 +341,7 @@ static int kvm_set_migration_log(int enable) > > s->migration_log = enable; > > - for (i = 0; i < ARRAY_SIZE(s->slots); i++) { > + for (i = 0; i < s->num_slots; i++) { > mem = &s->slots[i]; > > if (!mem->memory_size) { > @@ -1268,9 +1269,6 @@ int kvm_init(void) > #ifdef KVM_CAP_SET_GUEST_DEBUG > QTAILQ_INIT(&s->kvm_sw_breakpoints); > #endif > - for (i = 0; i < ARRAY_SIZE(s->slots); i++) { > - s->slots[i].slot = i; > - } > s->vmfd = -1; > s->fd = qemu_open("/dev/kvm", O_RDWR); > if (s->fd == -1) { > @@ -1324,6 +1322,16 @@ int kvm_init(void) > goto err; > } > > + s->num_slots = kvm_check_extension(s, KVM_CAP_NR_MEMSLOTS); > + if (s->num_slots <= 0) { kvm_check_extension() never returns negative value, so !s->num_slots check is enough. Other than that minor nit looks OK. > + s->num_slots = 32; > + } > + s->slots = g_malloc0(s->num_slots * sizeof(*s->slots)); > + > + for (i = 0; i < s->num_slots; i++) { > + s->slots[i].slot = i; > + } > + > s->coalesced_mmio = kvm_check_extension(s, KVM_CAP_COALESCED_MMIO); > > s->broken_set_mem_region = 1; > @@ -1393,6 +1401,7 @@ err: > if (s->fd != -1) { > close(s->fd); > } > + g_free(s->slots); > g_free(s); > > return ret; -- Gleb.