[PATCH v5 06/19] KVM: Drop kvm_arch_create_memslot()

Sean Christopherson
2020-01-21T22:34:43Z

Remove kvm_arch_create_memslot() now that all arch implementations are
effectively nops. Removing kvm_arch_create_memslot() eliminates the
possibility for arch specific code to allocate memory prior to setting
a memslot, which sets the stage for simplifying kvm_free_memslot().

Cc: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/mips/kvm/mips.c | 6 ------
arch/powerpc/kvm/powerpc.c | 6 ------
arch/s390/kvm/kvm-s390.c | 6 ------
arch/x86/kvm/x86.c | 6 ------
include/linux/kvm_host.h | 2 --
virt/kvm/arm/mmu.c | 6 ------
virt/kvm/kvm_main.c | 21 +++++++--------------
7 files changed, 7 insertions(+), 46 deletions(-)

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 2606f3f02b54..6d54e18ebdc1 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -188,12 +188,6 @@ long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl,
return -ENOIOCTLCMD;
}

-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
- unsigned long npages)
-{
- return 0;
-}
-
void kvm_arch_flush_shadow_all(struct kvm *kvm)
{
/* Flush whole GPA */
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 4e0f7a77920d..48abf1b9ad58 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -691,12 +691,6 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
kvmppc_core_free_memslot(kvm, free, dont);
}

-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
- unsigned long npages)
-{
- return 0;
-}
-
int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
const struct kvm_userspace_memory_region *mem,
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index c059b86aacd4..743e09dd38b5 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -4483,12 +4483,6 @@ vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
}

-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
- unsigned long npages)
-{
- return 0;
-}
-
/* Section: memory related */
int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 35a7e3d9b99a..b55bf2ecdd98 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9788,12 +9788,6 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
kvm_page_track_free_memslot(free, dont);
}

-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
- unsigned long npages)
-{
- return 0;
-}
-
static int kvm_alloc_memslot_metadata(struct kvm_memory_slot *slot,
unsigned long npages)
{
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6d5331b0d937..aa5cb2ff7a2b 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -671,8 +671,6 @@ int __kvm_set_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem);
void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
struct kvm_memory_slot *dont);
-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
- unsigned long npages);
void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen);
int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index dc8254bf30ea..66f59c067bf6 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -2356,12 +2356,6 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
{
}

-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
- unsigned long npages)
-{
- return 0;
-}
-
void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
{
}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8c9211182680..5e777ab02395 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1039,12 +1039,13 @@ int __kvm_set_memory_region(struct kvm *kvm,
new.base_gfn = base_gfn;
new.npages = npages;
new.flags = mem->flags;
+ new.userspace_addr = mem->userspace_addr;

if (npages) {
if (!old.npages)
change = KVM_MR_CREATE;
else { /* Modify an existing slot. */
- if ((mem->userspace_addr != old.userspace_addr) ||
+ if ((new.userspace_addr != old.userspace_addr) ||
(npages != old.npages) ||
((new.flags ^ old.flags) & KVM_MEM_READONLY))
goto out;
@@ -1079,22 +1080,14 @@ int __kvm_set_memory_region(struct kvm *kvm,
}
}

- /* Free page dirty bitmap if unneeded */
- if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
- new.dirty_bitmap = NULL;
-
r = -ENOMEM;
- if (change == KVM_MR_CREATE) {
- new.userspace_addr = mem->userspace_addr;

- if (kvm_arch_create_memslot(kvm, &new, npages))
- goto out;
- }
-
- /* Allocate page dirty bitmap if needed */
- if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
+ /* Allocate/free page dirty bitmap as needed */
+ if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
+ new.dirty_bitmap = NULL;
+ else if (!new.dirty_bitmap) {
if (kvm_create_dirty_bitmap(&new) < 0)
- goto out_free;
+ goto out;
}

slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL_ACCOUNT);
--
2.24.1