| Message ID | 20220816053937.2477106-4-seanjc@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: kvm_create_vm() bug fixes and cleanup | expand |
On Tue, Aug 16, 2022 at 05:39:37AM +0000, Sean Christopherson wrote: > Invoke kvm_coalesced_mmio_init() from kvm_create_vm() now that allocating > and initializing coalesced MMIO objects is separate from registering any > associated devices. Moving coalesced MMIO cleans up the last oddity > where KVM does VM creation/initialization after kvm_create_vm(), and more > importantly after kvm_arch_post_init_vm() is called and the VM is added > to the global vm_list, i.e. after the VM is fully created as far as KVM > is concerned. > > Originally, kvm_coalesced_mmio_init() was called by kvm_create_vm(), but > the original implementation was completely devoid of error handling. > Commit 6ce5a090a9a0 ("KVM: coalesced_mmio: fix kvm_coalesced_mmio_init()'s > error handling" fixed the various bugs, and in doing so rightly moved the > call to after kvm_create_vm() because kvm_coalesced_mmio_init() also > registered the coalesced MMIO device. Commit 2b3c246a682c ("KVM: Make > coalesced mmio use a device per zone") cleaned up that mess by having > each zone register a separate device, i.e. moved device registration to > its logical home in kvm_vm_ioctl_register_coalesced_mmio(). As a result, > kvm_coalesced_mmio_init() is now a "pure" initialization helper and can > be safely called from kvm_create_vm(). > > Opportunstically drop the #ifdef, KVM provides stubs for > kvm_coalesced_mmio_{init,free}() when CONFIG_KVM_MMIO=n (arm). ^^^ We have CONFIG_KVM_MMIO=y on arm64. Is it actually s390? -- Thanks, Oliver
On Tue, Aug 16, 2022, Oliver Upton wrote: > On Tue, Aug 16, 2022 at 05:39:37AM +0000, Sean Christopherson wrote: > > Invoke kvm_coalesced_mmio_init() from kvm_create_vm() now that allocating > > and initializing coalesced MMIO objects is separate from registering any > > associated devices. Moving coalesced MMIO cleans up the last oddity > > where KVM does VM creation/initialization after kvm_create_vm(), and more > > importantly after kvm_arch_post_init_vm() is called and the VM is added > > to the global vm_list, i.e. after the VM is fully created as far as KVM > > is concerned. > > > > Originally, kvm_coalesced_mmio_init() was called by kvm_create_vm(), but > > the original implementation was completely devoid of error handling. > > Commit 6ce5a090a9a0 ("KVM: coalesced_mmio: fix kvm_coalesced_mmio_init()'s > > error handling" fixed the various bugs, and in doing so rightly moved the > > call to after kvm_create_vm() because kvm_coalesced_mmio_init() also > > registered the coalesced MMIO device. Commit 2b3c246a682c ("KVM: Make > > coalesced mmio use a device per zone") cleaned up that mess by having > > each zone register a separate device, i.e. moved device registration to > > its logical home in kvm_vm_ioctl_register_coalesced_mmio(). As a result, > > kvm_coalesced_mmio_init() is now a "pure" initialization helper and can > > be safely called from kvm_create_vm(). > > > > Opportunstically drop the #ifdef, KVM provides stubs for > > kvm_coalesced_mmio_{init,free}() when CONFIG_KVM_MMIO=n (arm). > ^^^ > We have CONFIG_KVM_MMIO=y on arm64. Is it actually s390? Yes, I apparently can't read.
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 15e304e059d4..44b92d773156 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1214,6 +1214,10 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) if (r) goto out_err_no_mmu_notifier; + r = kvm_coalesced_mmio_init(kvm); + if (r < 0) + goto out_no_coalesced_mmio; + r = kvm_create_vm_debugfs(kvm, fdname); if (r) goto out_err_no_debugfs; @@ -1234,6 +1238,8 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) out_err: kvm_destroy_vm_debugfs(kvm); out_err_no_debugfs: + kvm_coalesced_mmio_free(kvm); +out_no_coalesced_mmio: #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER) if (kvm->mmu_notifier.ops) mmu_notifier_unregister(&kvm->mmu_notifier, current->mm); @@ -4907,11 +4913,6 @@ static int kvm_dev_ioctl_create_vm(unsigned long type) goto put_fd; } -#ifdef CONFIG_KVM_MMIO - r = kvm_coalesced_mmio_init(kvm); - if (r < 0) - goto put_kvm; -#endif file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR); if (IS_ERR(file)) { r = PTR_ERR(file);
Invoke kvm_coalesced_mmio_init() from kvm_create_vm() now that allocating and initializing coalesced MMIO objects is separate from registering any associated devices. Moving coalesced MMIO cleans up the last oddity where KVM does VM creation/initialization after kvm_create_vm(), and more importantly after kvm_arch_post_init_vm() is called and the VM is added to the global vm_list, i.e. after the VM is fully created as far as KVM is concerned. Originally, kvm_coalesced_mmio_init() was called by kvm_create_vm(), but the original implementation was completely devoid of error handling. Commit 6ce5a090a9a0 ("KVM: coalesced_mmio: fix kvm_coalesced_mmio_init()'s error handling" fixed the various bugs, and in doing so rightly moved the call to after kvm_create_vm() because kvm_coalesced_mmio_init() also registered the coalesced MMIO device. Commit 2b3c246a682c ("KVM: Make coalesced mmio use a device per zone") cleaned up that mess by having each zone register a separate device, i.e. moved device registration to its logical home in kvm_vm_ioctl_register_coalesced_mmio(). As a result, kvm_coalesced_mmio_init() is now a "pure" initialization helper and can be safely called from kvm_create_vm(). Opportunstically drop the #ifdef, KVM provides stubs for kvm_coalesced_mmio_{init,free}() when CONFIG_KVM_MMIO=n (arm). Signed-off-by: Sean Christopherson <seanjc@google.com> --- virt/kvm/kvm_main.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)