From f69bd1c99d908b9de5ba4f335a55597a3e8fd947 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Alex Williamson Date: Mon, 9 Dec 2013 17:52:56 +0100 Subject: [PATCH 07/16] kvm: Query KVM for available memory slots RH-Author: Alex Williamson Message-id: <20131209175223.22125.66085.stgit@bling.home> Patchwork-id: 56092 O-Subject: [RHEL7 qemu-kvm PATCH] kvm: Query KVM for available memory slots Bugzilla: 921490 RH-Acked-by: Paolo Bonzini RH-Acked-by: Eduardo Habkost RH-Acked-by: Bandan Das RH-Acked-by: Amos Kong Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=921490 Brew: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=6696277 Upstream: fb541ca59c8b55911821c9f794c3dbe5de9ba9d8 KVM reports the number of available memory slots (KVM_CAP_NR_MEMSLOTS) using the extension interface. Both x86 and s390 implement this, ARM and powerpc do not yet enable it. Convert the static slots array to be dynamically allocated, supporting more slots when available. Default to 32 when KVM_CAP_NR_MEMSLOTS is not implemented. The motivation for this change is to support more assigned devices, where memory mapped PCI MMIO BARs typically take one slot each. Signed-off-by: Alex Williamson Reviewed-by: Thomas Huth Signed-off-by: Paolo Bonzini --- kvm-all.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) Signed-off-by: Michal Novotny --- kvm-all.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index f2f68d6..0e21494 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -72,7 +72,8 @@ typedef struct kvm_dirty_log KVMDirtyLog; struct KVMState { - KVMSlot slots[32]; + KVMSlot *slots; + int nr_slots; int fd; int vmfd; int coalesced_mmio; @@ -122,7 +123,7 @@ static KVMSlot *kvm_alloc_slot(KVMState *s) { int i; - for (i = 0; i < ARRAY_SIZE(s->slots); i++) { + for (i = 0; i < s->nr_slots; i++) { if (s->slots[i].memory_size == 0) { return &s->slots[i]; } @@ -138,7 +139,7 @@ static KVMSlot *kvm_lookup_matching_slot(KVMState *s, { int i; - for (i = 0; i < ARRAY_SIZE(s->slots); i++) { + for (i = 0; i < s->nr_slots; i++) { KVMSlot *mem = &s->slots[i]; if (start_addr == mem->start_addr && @@ -160,7 +161,7 @@ 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->nr_slots; i++) { KVMSlot *mem = &s->slots[i]; if (mem->memory_size == 0 || @@ -182,7 +183,7 @@ 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->nr_slots; i++) { KVMSlot *mem = &s->slots[i]; if (ram >= mem->ram && ram < mem->ram + mem->memory_size) { @@ -342,7 +343,7 @@ 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->nr_slots; i++) { mem = &s->slots[i]; if (!mem->memory_size) { @@ -1328,9 +1329,6 @@ 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) { @@ -1354,6 +1352,19 @@ int kvm_init(void) goto err; } + s->nr_slots = kvm_check_extension(s, KVM_CAP_NR_MEMSLOTS); + + /* If unspecified, use the default value */ + if (!s->nr_slots) { + s->nr_slots = 32; + } + + s->slots = g_malloc0(s->nr_slots * sizeof(KVMSlot)); + + for (i = 0; i < s->nr_slots; i++) { + s->slots[i].slot = i; + } + /* check the vcpu limits */ soft_vcpus_limit = kvm_recommended_vcpus(s); hard_vcpus_limit = kvm_max_vcpus(s); @@ -1467,6 +1478,7 @@ err: if (s->fd != -1) { close(s->fd); } + g_free(s->slots); g_free(s); return ret; -- 1.7.11.7