diff mbox

[kvmtool,04/10] Extend memory bank API with memory types

Message ID 20170331175450.24269-5-jean-philippe.brucker@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jean-Philippe Brucker March 31, 2017, 5:54 p.m. UTC
Introduce memory types RAM and DEVICE, along with a way for components to
query the global memory banks. This is required by VFIO, which will need
to pin and map guest RAM so that passed-through devices can safely do DMA
to it. Depending on the architecture, the physical map is made of either
one or two RAM regions. In addition, this new memory types API paves the
way to reserved memory regions introduced in a subsequent patch.

For the moment we put vesa and ivshmem memory into the DEVICE category, so
they don't have to be pinned. This means that physical devices passed
through with VFIO won't be able to DMA to the vesa frame buffer or
ivshmem. In order to do that, simply changing the type to "RAM" would
work. But to keep the types consistent, it would be better to introduce
flags such as KVM_MEM_TYPE_DMA that would complement both RAM and DEVICE
type. We could then reuse the API for generating firmware information
(that is, for x86 bios; DT supports reserved-memory description).

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
---
 arm/kvm.c         |  2 +-
 hw/pci-shmem.c    |  4 ++--
 hw/vesa.c         |  2 +-
 include/kvm/kvm.h | 44 +++++++++++++++++++++++++++++++++++++++++++-
 kvm.c             | 31 ++++++++++++++++++++++++++++++-
 mips/kvm.c        |  6 +++---
 powerpc/kvm.c     |  2 +-
 x86/kvm.c         |  6 +++---
 8 files changed, 84 insertions(+), 13 deletions(-)
diff mbox

Patch

diff --git a/arm/kvm.c b/arm/kvm.c
index 3cfa90ab..77d98281 100644
--- a/arm/kvm.c
+++ b/arm/kvm.c
@@ -34,7 +34,7 @@  void kvm__init_ram(struct kvm *kvm)
 	phys_size	= kvm->ram_size;
 	host_mem	= kvm->ram_start;
 
-	err = kvm__register_mem(kvm, phys_start, phys_size, host_mem);
+	err = kvm__register_ram(kvm, phys_start, phys_size, host_mem);
 	if (err)
 		die("Failed to register %lld bytes of memory at physical "
 		    "address 0x%llx [err %d]", phys_size, phys_start, err);
diff --git a/hw/pci-shmem.c b/hw/pci-shmem.c
index 107043e9..f92bc755 100644
--- a/hw/pci-shmem.c
+++ b/hw/pci-shmem.c
@@ -387,8 +387,8 @@  int pci_shmem__init(struct kvm *kvm)
 	if (mem == NULL)
 		return -EINVAL;
 
-	kvm__register_mem(kvm, shmem_region->phys_addr, shmem_region->size,
-			  mem);
+	kvm__register_dev_mem(kvm, shmem_region->phys_addr, shmem_region->size,
+			      mem);
 	return 0;
 }
 dev_init(pci_shmem__init);
diff --git a/hw/vesa.c b/hw/vesa.c
index a9a1d3e2..f3c5114c 100644
--- a/hw/vesa.c
+++ b/hw/vesa.c
@@ -73,7 +73,7 @@  struct framebuffer *vesa__init(struct kvm *kvm)
 	if (mem == MAP_FAILED)
 		ERR_PTR(-errno);
 
-	kvm__register_mem(kvm, VESA_MEM_ADDR, VESA_MEM_SIZE, mem);
+	kvm__register_dev_mem(kvm, VESA_MEM_ADDR, VESA_MEM_SIZE, mem);
 
 	vesafb = (struct framebuffer) {
 		.width			= VESA_WIDTH,
diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h
index a76a25d2..4691bb5d 100644
--- a/include/kvm/kvm.h
+++ b/include/kvm/kvm.h
@@ -34,6 +34,14 @@  enum {
 	KVM_VMSTATE_PAUSED,
 };
 
+enum kvm_mem_type {
+	KVM_MEM_TYPE_RAM	= 1 << 1,
+	KVM_MEM_TYPE_DEVICE	= 1 << 2,
+
+	KVM_MEM_TYPE_ALL	= KVM_MEM_TYPE_RAM
+				| KVM_MEM_TYPE_DEVICE
+};
+
 struct kvm_ext {
 	const char *name;
 	int code;
@@ -44,6 +52,7 @@  struct kvm_mem_bank {
 	u64			guest_phys_addr;
 	void			*host_addr;
 	u64			size;
+	enum kvm_mem_type	type;
 };
 
 struct kvm {
@@ -89,7 +98,22 @@  void kvm__irq_line(struct kvm *kvm, int irq, int level);
 void kvm__irq_trigger(struct kvm *kvm, int irq);
 bool kvm__emulate_io(struct kvm_cpu *vcpu, u16 port, void *data, int direction, int size, u32 count);
 bool kvm__emulate_mmio(struct kvm_cpu *vcpu, u64 phys_addr, u8 *data, u32 len, u8 is_write);
-int kvm__register_mem(struct kvm *kvm, u64 guest_phys, u64 size, void *userspace_addr);
+int kvm__register_mem(struct kvm *kvm, u64 guest_phys, u64 size, void *userspace_addr,
+		      enum kvm_mem_type type);
+static inline int kvm__register_ram(struct kvm *kvm, u64 guest_phys, u64 size,
+				    void *userspace_addr)
+{
+	return kvm__register_mem(kvm, guest_phys, size, userspace_addr,
+				 KVM_MEM_TYPE_RAM);
+}
+
+static inline int kvm__register_dev_mem(struct kvm *kvm, u64 guest_phys,
+					u64 size, void *userspace_addr)
+{
+	return kvm__register_mem(kvm, guest_phys, size, userspace_addr,
+				 KVM_MEM_TYPE_DEVICE);
+}
+
 int kvm__register_mmio(struct kvm *kvm, u64 phys_addr, u64 phys_addr_len, bool coalesce,
 		       void (*mmio_fn)(struct kvm_cpu *vcpu, u64 addr, u8 *data, u32 len, u8 is_write, void *ptr),
 			void *ptr);
@@ -116,6 +140,24 @@  u64 host_to_guest_flat(struct kvm *kvm, void *ptr);
 bool kvm__arch_load_kernel_image(struct kvm *kvm, int fd_kernel, int fd_initrd,
 				 const char *kernel_cmdline);
 
+static inline const char *kvm_mem_type_to_string(enum kvm_mem_type type)
+{
+	switch (type) {
+	case KVM_MEM_TYPE_ALL:
+		return "(all)";
+	case KVM_MEM_TYPE_RAM:
+		return "RAM";
+	case KVM_MEM_TYPE_DEVICE:
+		return "device";
+	}
+
+	return "???";
+}
+
+int kvm__for_each_mem_bank(struct kvm *kvm, enum kvm_mem_type type,
+			   int (*fun)(struct kvm *kvm, struct kvm_mem_bank *bank, void *data),
+			   void *data);
+
 /*
  * Debugging
  */
diff --git a/kvm.c b/kvm.c
index 665ed148..39ce88c4 100644
--- a/kvm.c
+++ b/kvm.c
@@ -182,7 +182,8 @@  core_exit(kvm__exit);
  * memory regions to it. Therefore, be careful if you use this function for
  * registering memory regions for emulating hardware.
  */
-int kvm__register_mem(struct kvm *kvm, u64 guest_phys, u64 size, void *userspace_addr)
+int kvm__register_mem(struct kvm *kvm, u64 guest_phys, u64 size,
+		      void *userspace_addr, enum kvm_mem_type type)
 {
 	struct kvm_userspace_memory_region mem;
 	struct kvm_mem_bank *bank;
@@ -196,6 +197,7 @@  int kvm__register_mem(struct kvm *kvm, u64 guest_phys, u64 size, void *userspace
 	bank->guest_phys_addr		= guest_phys;
 	bank->host_addr			= userspace_addr;
 	bank->size			= size;
+	bank->type			= type;
 
 	mem = (struct kvm_userspace_memory_region) {
 		.slot			= kvm->mem_slots++,
@@ -245,6 +247,33 @@  u64 host_to_guest_flat(struct kvm *kvm, void *ptr)
 	return 0;
 }
 
+/*
+ * Iterate over each registered memory bank. Call @fun for each bank with @data
+ * as argument. @type is a bitmask that allows to filter banks according to
+ * their type.
+ *
+ * If one call to @fun returns a non-zero value, stop iterating and return the
+ * value. Otherwise, return zero.
+ */
+int kvm__for_each_mem_bank(struct kvm *kvm, enum kvm_mem_type type,
+			   int (*fun)(struct kvm *kvm, struct kvm_mem_bank *bank, void *data),
+			   void *data)
+{
+	int ret;
+	struct kvm_mem_bank *bank;
+
+	list_for_each_entry(bank, &kvm->mem_banks, list) {
+		if (type != KVM_MEM_TYPE_ALL && !(bank->type & type))
+			continue;
+
+		ret = fun(kvm, bank, data);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
 int kvm__recommended_cpus(struct kvm *kvm)
 {
 	int ret;
diff --git a/mips/kvm.c b/mips/kvm.c
index 24bd6507..211770da 100644
--- a/mips/kvm.c
+++ b/mips/kvm.c
@@ -28,21 +28,21 @@  void kvm__init_ram(struct kvm *kvm)
 		phys_size  = kvm->ram_size;
 		host_mem   = kvm->ram_start;
 
-		kvm__register_mem(kvm, phys_start, phys_size, host_mem);
+		kvm__register_ram(kvm, phys_start, phys_size, host_mem);
 	} else {
 		/* one region for memory that fits below MMIO range */
 		phys_start = 0;
 		phys_size  = KVM_MMIO_START;
 		host_mem   = kvm->ram_start;
 
-		kvm__register_mem(kvm, phys_start, phys_size, host_mem);
+		kvm__register_ram(kvm, phys_start, phys_size, host_mem);
 
 		/* one region for rest of memory */
 		phys_start = KVM_MMIO_START + KVM_MMIO_SIZE;
 		phys_size  = kvm->ram_size - KVM_MMIO_START;
 		host_mem   = kvm->ram_start + KVM_MMIO_START;
 
-		kvm__register_mem(kvm, phys_start, phys_size, host_mem);
+		kvm__register_ram(kvm, phys_start, phys_size, host_mem);
 	}
 }
 
diff --git a/powerpc/kvm.c b/powerpc/kvm.c
index c738c1d6..702d67dc 100644
--- a/powerpc/kvm.c
+++ b/powerpc/kvm.c
@@ -79,7 +79,7 @@  void kvm__init_ram(struct kvm *kvm)
 		    "overlaps MMIO!\n",
 		    phys_size);
 
-	kvm__register_mem(kvm, phys_start, phys_size, host_mem);
+	kvm__register_ram(kvm, phys_start, phys_size, host_mem);
 }
 
 void kvm__arch_set_cmdline(char *cmdline, bool video)
diff --git a/x86/kvm.c b/x86/kvm.c
index bfa04b81..8ee58e83 100644
--- a/x86/kvm.c
+++ b/x86/kvm.c
@@ -98,7 +98,7 @@  void kvm__init_ram(struct kvm *kvm)
 		phys_size  = kvm->ram_size;
 		host_mem   = kvm->ram_start;
 
-		kvm__register_mem(kvm, phys_start, phys_size, host_mem);
+		kvm__register_ram(kvm, phys_start, phys_size, host_mem);
 	} else {
 		/* First RAM range from zero to the PCI gap: */
 
@@ -106,7 +106,7 @@  void kvm__init_ram(struct kvm *kvm)
 		phys_size  = KVM_32BIT_GAP_START;
 		host_mem   = kvm->ram_start;
 
-		kvm__register_mem(kvm, phys_start, phys_size, host_mem);
+		kvm__register_ram(kvm, phys_start, phys_size, host_mem);
 
 		/* Second RAM range from 4GB to the end of RAM: */
 
@@ -114,7 +114,7 @@  void kvm__init_ram(struct kvm *kvm)
 		phys_size  = kvm->ram_size - phys_start;
 		host_mem   = kvm->ram_start + phys_start;
 
-		kvm__register_mem(kvm, phys_start, phys_size, host_mem);
+		kvm__register_ram(kvm, phys_start, phys_size, host_mem);
 	}
 }