[PATCH v2 19/50] KVM: arm64: Do arm/arch initialization without bouncing through kvm_init()
From: Sean Christopherson <seanjc@google.com>
Date: 2022-11-30 23:13:04
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-mips, linux-riscv, linux-s390, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Do arm/arch specific initialization directly in arm's module_init(), now called kvm_arm_init(), instead of bouncing through kvm_init() to reach kvm_arch_init(). Invoking kvm_arch_init() is the very first action performed by kvm_init(), so from a initialization perspective this is a glorified nop. Avoiding kvm_arch_init() also fixes a mostly benign bug as kvm_arch_exit() doesn't properly unwind if a later stage of kvm_init() fails. While the soon-to-be-deleted comment about compiling as a module being unsupported is correct, kvm_arch_exit() can still be called by kvm_init() if any step after the call to kvm_arch_init() succeeds. Add a FIXME to call out that pKVM initialization isn't unwound if kvm_init() fails, which is a pre-existing problem inherited from kvm_arch_exit(). Making kvm_arch_init() a nop will also allow dropping kvm_arch_init() and kvm_arch_exit() entirely once all other architectures follow suit. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/arm64/kvm/arm.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e6f6fcfe6bcc..d3a4db1abf32 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c@@ -2195,7 +2195,7 @@ void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons) /** * Initialize Hyp-mode and memory mappings on all CPUs. */ -int kvm_arch_init(void *opaque) +int kvm_arm_init(void) { int err; bool in_hyp_mode;
@@ -2269,6 +2269,14 @@ int kvm_arch_init(void *opaque) kvm_info("Hyp mode initialized successfully\n"); } + /* + * FIXME: Do something reasonable if kvm_init() fails after pKVM + * hypervisor protection is finalized. + */ + err = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE); + if (err) + goto out_subs; + return 0; out_subs:
@@ -2281,10 +2289,15 @@ int kvm_arch_init(void *opaque) return err; } +int kvm_arch_init(void *opaque) +{ + return 0; +} + /* NOP: Compiling as a module not supported */ void kvm_arch_exit(void) { - kvm_unregister_perf_callbacks(); + } static int __init early_kvm_mode_cfg(char *arg)
@@ -2325,10 +2338,4 @@ enum kvm_mode kvm_get_mode(void) return kvm_mode; } -static int arm_init(void) -{ - int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE); - return rc; -} - -module_init(arm_init); +module_init(kvm_arm_init);
--
2.38.1.584.g0f3c55d4c2-goog