kvm: make KVM_COALESCED_MMIO_PAGE_OFFSET public

Its value has never changed; we might as well make it part of the ABI instead
of using the return value of KVM_CHECK_EXTENSION(KVM_CAP_COALESCED_MMIO).

Because PPC does not always make MMIO available, the code has to be made
dependent on CONFIG_KVM_MMIO rather than KVM_COALESCED_MMIO_PAGE_OFFSET.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

arch/arm/include/asm/kvm_host.h

@@ -30,7 +30,6 @@
 #define __KVM_HAVE_ARCH_INTC_INITIALIZED
 
 #define KVM_USER_MEM_SLOTS 32
-#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
 #define KVM_HAVE_ONE_REG
 #define KVM_HALT_POLL_NS_DEFAULT 500000
 

arch/arm/include/uapi/asm/kvm.h

@@ -27,6 +27,8 @@
 #define __KVM_HAVE_IRQ_LINE
 #define __KVM_HAVE_READONLY_MEM
 
+#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+
 #define KVM_REG_SIZE(id)						\
 	(1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT))
 

arch/arm64/include/asm/kvm_host.h

@@ -31,7 +31,6 @@
 #define __KVM_HAVE_ARCH_INTC_INITIALIZED
 
 #define KVM_USER_MEM_SLOTS 512
-#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
 #define KVM_HALT_POLL_NS_DEFAULT 500000
 
 #include <kvm/arm_vgic.h>

arch/arm64/include/uapi/asm/kvm.h

@@ -39,6 +39,8 @@
 #define __KVM_HAVE_IRQ_LINE
 #define __KVM_HAVE_READONLY_MEM
 
+#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+
 #define KVM_REG_SIZE(id)						\
 	(1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT))
 

arch/mips/include/asm/kvm_host.h

@@ -83,7 +83,6 @@
 /* memory slots that does not exposed to userspace */
 #define KVM_PRIVATE_MEM_SLOTS	0
 
-#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
 #define KVM_HALT_POLL_NS_DEFAULT 500000
 
 #ifdef CONFIG_KVM_MIPS_VZ

arch/mips/include/uapi/asm/kvm.h

@@ -21,6 +21,8 @@
 
 #define __KVM_HAVE_READONLY_MEM
 
+#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+
 /*
  * for KVM_GET_REGS and KVM_SET_REGS
  *

arch/powerpc/include/asm/kvm_host.h

@@ -45,9 +45,6 @@
 
 #define __KVM_HAVE_ARCH_INTC_INITIALIZED
 
-#ifdef CONFIG_KVM_MMIO
-#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
-#endif
 #define KVM_HALT_POLL_NS_DEFAULT 10000	/* 10 us */
 
 /* These values are internal and can be increased later */

arch/powerpc/include/uapi/asm/kvm.h

@@ -29,6 +29,9 @@
 #define __KVM_HAVE_IRQ_LINE
 #define __KVM_HAVE_GUEST_DEBUG
 
+/* Not always available, but if it is, this is the correct offset.  */
+#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+
 struct kvm_regs {
 	__u64 pc;
 	__u64 cr;

arch/x86/include/asm/kvm_host.h

@@ -43,8 +43,6 @@
 #define KVM_PRIVATE_MEM_SLOTS 3
 #define KVM_MEM_SLOTS_NUM (KVM_USER_MEM_SLOTS + KVM_PRIVATE_MEM_SLOTS)
 
-#define KVM_PIO_PAGE_OFFSET 1
-#define KVM_COALESCED_MMIO_PAGE_OFFSET 2
 #define KVM_HALT_POLL_NS_DEFAULT 400000
 
 #define KVM_IRQCHIP_NUM_PINS  KVM_IOAPIC_NUM_PINS

arch/x86/include/uapi/asm/kvm.h

@@ -9,6 +9,9 @@
 #include <linux/types.h>
 #include <linux/ioctl.h>
 
+#define KVM_PIO_PAGE_OFFSET 1
+#define KVM_COALESCED_MMIO_PAGE_OFFSET 2
+
 #define DE_VECTOR 0
 #define DB_VECTOR 1
 #define BP_VECTOR 3

include/linux/kvm_host.h

@@ -403,7 +403,7 @@ struct kvm {
 	struct kvm_vm_stat stat;
 	struct kvm_arch arch;
 	refcount_t users_count;
-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+#ifdef CONFIG_KVM_MMIO
 	struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
 	spinlock_t ring_lock;
 	struct list_head coalesced_zones;

virt/kvm/kvm_main.c

@@ -2349,7 +2349,7 @@ static int kvm_vcpu_fault(struct vm_fault *vmf)
 	else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
 		page = virt_to_page(vcpu->arch.pio_data);
 #endif
-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+#ifdef CONFIG_KVM_MMIO
 	else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
 		page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
 #endif
@@ -2918,7 +2918,7 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
 	case KVM_CAP_IOEVENTFD_ANY_LENGTH:
 	case KVM_CAP_CHECK_EXTENSION_VM:
 		return 1;
-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+#ifdef CONFIG_KVM_MMIO
 	case KVM_CAP_COALESCED_MMIO:
 		return KVM_COALESCED_MMIO_PAGE_OFFSET;
 #endif
@@ -2971,7 +2971,7 @@ static long kvm_vm_ioctl(struct file *filp,
 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
 		break;
 	}
-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+#ifdef CONFIG_KVM_MMIO
 	case KVM_REGISTER_COALESCED_MMIO: {
 		struct kvm_coalesced_mmio_zone zone;
 
@@ -3163,7 +3163,7 @@ static int kvm_dev_ioctl_create_vm(unsigned long type)
 	kvm = kvm_create_vm(type);
 	if (IS_ERR(kvm))
 		return PTR_ERR(kvm);
-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+#ifdef CONFIG_KVM_MMIO
 	r = kvm_coalesced_mmio_init(kvm);
 	if (r < 0) {
 		kvm_put_kvm(kvm);
@@ -3216,7 +3216,7 @@ static long kvm_dev_ioctl(struct file *filp,
 #ifdef CONFIG_X86
 		r += PAGE_SIZE;    /* pio data page */
 #endif
-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+#ifdef CONFIG_KVM_MMIO
 		r += PAGE_SIZE;    /* coalesced mmio ring page */
 #endif
 		break;