[PULL 02/15] pc: kvm: check if KVM has free memory slots to avoid abort()

[PULL 02/15] pc: kvm: check if KVM has free memory slots to avoid abort()

[Michael S. Tsirkin]

From: Igor Mammedov <imammedo@redhat.com>

When more memory devices are used than available
KVM memory slots, QEMU crashes with:

kvm_alloc_slot: no free slot available
Aborted (core dumped)

Fix this by checking that KVM has a free slot before
attempting to map memory in guest address space.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/sysemu/kvm.h |  1 +
 hw/i386/pc.c         |  5 +++++
 kvm-all.c            | 18 +++++++++++++++++-
 kvm-stub.c           |  5 +++++
 4 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index b0cd657..22e42ef 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -163,6 +163,7 @@ extern KVMState *kvm_state;
 
 /* external API */
 
+bool kvm_has_free_slot(MachineState *ms);
 int kvm_has_sync_mmu(void);
 int kvm_has_vcpu_events(void);
 int kvm_has_robust_singlestep(void);
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 1205db8..ce7b752 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1598,6 +1598,11 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
         goto out;
     }
 
+    if (kvm_enabled() && !kvm_has_free_slot(machine)) {
+        error_setg(&local_err, "hypervisor has no free memory slots left");
+        goto out;
+    }
+
     memory_region_add_subregion(&pcms->hotplug_memory,
                                 addr - pcms->hotplug_memory_base, mr);
     vmstate_register_ram(mr, dev);
diff --git a/kvm-all.c b/kvm-all.c
index 596e7ce..937bc9d 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -132,7 +132,7 @@ static const KVMCapabilityInfo kvm_required_capabilites[] = {
     KVM_CAP_LAST_INFO
 };
 
-static KVMSlot *kvm_alloc_slot(KVMState *s)
+static KVMSlot *kvm_get_free_slot(KVMState *s)
 {
     int i;
 
@@ -142,6 +142,22 @@ static KVMSlot *kvm_alloc_slot(KVMState *s)
         }
     }
 
+    return NULL;
+}
+
+bool kvm_has_free_slot(MachineState *ms)
+{
+    return kvm_get_free_slot(KVM_STATE(ms->accelerator));
+}
+
+static KVMSlot *kvm_alloc_slot(KVMState *s)
+{
+    KVMSlot *slot = kvm_get_free_slot(s);
+
+    if (slot) {
+        return slot;
+    }
+
     fprintf(stderr, "%s: no free slot available\n", __func__);
     abort();
 }
diff --git a/kvm-stub.c b/kvm-stub.c
index 43fc0dd..7ba90c5 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -147,4 +147,9 @@ int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int virq)
 {
     return -ENOSYS;
 }
+
+bool kvm_has_free_slot(MachineState *ms)
+{
+    return false;
+}
 #endif
-- 
MST

[PULL 05/15] memory: expose alignment used for allocating RAM as MemoryRegion API

[Michael S. Tsirkin]

From: Igor Mammedov <imammedo@redhat.com>

introduce memory_region_get_alignment() that returns
underlying memory block alignment or 0 if it's not
relevant/implemented for backend.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/exec/exec-all.h | 2 +-
 include/exec/memory.h   | 2 ++
 include/qemu/osdep.h    | 3 ++-
 exec.c                  | 9 ++++++---
 memory.c                | 5 +++++
 target-s390x/kvm.c      | 2 +-
 util/oslib-posix.c      | 5 ++++-
 util/oslib-win32.c      | 2 +-
 8 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 421a142..0844885 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -333,7 +333,7 @@ extern uintptr_t tci_tb_ptr;
 
 #if !defined(CONFIG_USER_ONLY)
 
-void phys_mem_set_alloc(void *(*alloc)(size_t));
+void phys_mem_set_alloc(void *(*alloc)(size_t, uint64_t *align));
 
 struct MemoryRegion *iotlb_to_region(AddressSpace *as, hwaddr index);
 bool io_mem_read(struct MemoryRegion *mr, hwaddr addr,
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 74a58b4..f64ab5e 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -146,6 +146,7 @@ struct MemoryRegion {
     hwaddr addr;
     void (*destructor)(MemoryRegion *mr);
     ram_addr_t ram_addr;
+    uint64_t align;
     bool subpage;
     bool terminates;
     bool romd_mode;
@@ -838,6 +839,7 @@ void memory_region_add_subregion_overlap(MemoryRegion *mr,
  */
 ram_addr_t memory_region_get_ram_addr(MemoryRegion *mr);
 
+uint64_t memory_region_get_alignment(const MemoryRegion *mr);
 /**
  * memory_region_del_subregion: Remove a subregion.
  *
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index c032434..b3300cc 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -5,6 +5,7 @@
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdbool.h>
+#include <stdint.h>
 #include <sys/types.h>
 #ifdef __OpenBSD__
 #include <sys/signal.h>
@@ -103,7 +104,7 @@ typedef signed int              int_fast16_t;
 int qemu_daemon(int nochdir, int noclose);
 void *qemu_try_memalign(size_t alignment, size_t size);
 void *qemu_memalign(size_t alignment, size_t size);
-void *qemu_anon_ram_alloc(size_t size);
+void *qemu_anon_ram_alloc(size_t size, uint64_t *align);
 void qemu_vfree(void *ptr);
 void qemu_anon_ram_free(void *ptr, size_t size);
 
diff --git a/exec.c b/exec.c
index f0e2bd3..71ac104 100644
--- a/exec.c
+++ b/exec.c
@@ -909,14 +909,15 @@ static int subpage_register (subpage_t *mmio, uint32_t start, uint32_t end,
                              uint16_t section);
 static subpage_t *subpage_init(AddressSpace *as, hwaddr base);
 
-static void *(*phys_mem_alloc)(size_t size) = qemu_anon_ram_alloc;
+static void *(*phys_mem_alloc)(size_t size, uint64_t *align) =
+                               qemu_anon_ram_alloc;
 
 /*
  * Set a custom physical guest memory alloator.
  * Accelerators with unusual needs may need this.  Hopefully, we can
  * get rid of it eventually.
  */
-void phys_mem_set_alloc(void *(*alloc)(size_t))
+void phys_mem_set_alloc(void *(*alloc)(size_t, uint64_t *align))
 {
     phys_mem_alloc = alloc;
 }
@@ -1098,6 +1099,7 @@ static void *file_ram_alloc(RAMBlock *block,
         error_propagate(errp, local_err);
         goto error;
     }
+    block->mr->align = hpagesize;
 
     if (memory < hpagesize) {
         error_setg(errp, "memory size 0x" RAM_ADDR_FMT " must be equal to "
@@ -1309,7 +1311,8 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp)
         if (xen_enabled()) {
             xen_ram_alloc(new_block->offset, new_block->length, new_block->mr);
         } else {
-            new_block->host = phys_mem_alloc(new_block->length);
+            new_block->host = phys_mem_alloc(new_block->length,
+                                             &new_block->mr->align);
             if (!new_block->host) {
                 error_setg_errno(errp, errno,
                                  "cannot set up guest memory '%s'",
diff --git a/memory.c b/memory.c
index 0f4fdc7..15cf9eb 100644
--- a/memory.c
+++ b/memory.c
@@ -1749,6 +1749,11 @@ ram_addr_t memory_region_get_ram_addr(MemoryRegion *mr)
     return mr->ram_addr;
 }
 
+uint64_t memory_region_get_alignment(const MemoryRegion *mr)
+{
+    return mr->align;
+}
+
 static int cmp_flatrange_addr(const void *addr_, const void *fr_)
 {
     const AddrRange *addr = addr_;
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index d247471..50709ba 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -404,7 +404,7 @@ int kvm_arch_get_registers(CPUState *cs)
  * to grow. We also have to use MAP parameters that avoid
  * read-only mapping of guest pages.
  */
-static void *legacy_s390_alloc(size_t size)
+static void *legacy_s390_alloc(size_t size, , uint64_t *align)
 {
     void *mem;
 
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 8c9d80e..16fcec2 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -124,7 +124,7 @@ void *qemu_memalign(size_t alignment, size_t size)
 }
 
 /* alloc shared memory pages */
-void *qemu_anon_ram_alloc(size_t size)
+void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
 {
     size_t align = QEMU_VMALLOC_ALIGN;
     size_t total = size + align - getpagesize();
@@ -136,6 +136,9 @@ void *qemu_anon_ram_alloc(size_t size)
         return NULL;
     }
 
+    if (alignment) {
+        *alignment = align;
+    }
     ptr += offset;
     total -= offset;
 
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index a3eab4a..87cfbe0 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -67,7 +67,7 @@ void *qemu_memalign(size_t alignment, size_t size)
     return qemu_oom_check(qemu_try_memalign(alignment, size));
 }
 
-void *qemu_anon_ram_alloc(size_t size)
+void *qemu_anon_ram_alloc(size_t size, uint64_t *align)
 {
     void *ptr;
 
-- 
MST