diff options
| author | Sean Christopherson <seanjc@google.com> | 2025-05-02 07:24:01 -0700 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-08-18 14:23:08 +0200 |
| commit | 2d1435b742156f6d4adc8b9ab0f24b35d879266e (patch) | |
| tree | 47fbc27afebba7e80e7481248af2ddf1a857a5f8 | |
| parent | c8ed0812646e1335c80a8f204c1b92b2f9d76119 (diff) | |
x86/fred: Install system vector handlers even if FRED isn't fully enabled
Install the system vector IRQ handlers for FRED even if FRED isn't fully
enabled in hardware. This will allow KVM to use the FRED IRQ path even
on non-FRED hardware, which in turn will eliminate a non-CFI indirect CALL
(KVM currently invokes the IRQ handler via an IDT lookup on the vector).
[sean: extract from diff, drop stub, write changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250714103441.121251108@infradead.org
| -rw-r--r-- | arch/x86/include/asm/idtentry.h | 9 | ||||
| -rw-r--r-- | arch/x86/kernel/irqinit.c | 6 |
2 files changed, 6 insertions, 9 deletions
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h index a4ec27c67988..abd637e54e94 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -460,17 +460,12 @@ __visible noinstr void func(struct pt_regs *regs, \ #endif void idt_install_sysvec(unsigned int n, const void *function); - -#ifdef CONFIG_X86_FRED void fred_install_sysvec(unsigned int vector, const idtentry_t function); -#else -static inline void fred_install_sysvec(unsigned int vector, const idtentry_t function) { } -#endif #define sysvec_install(vector, function) { \ - if (cpu_feature_enabled(X86_FEATURE_FRED)) \ + if (IS_ENABLED(CONFIG_X86_FRED)) \ fred_install_sysvec(vector, function); \ - else \ + if (!cpu_feature_enabled(X86_FEATURE_FRED)) \ idt_install_sysvec(vector, asm_##function); \ } diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c index f79c5edc0b89..6ab9eac64670 100644 --- a/arch/x86/kernel/irqinit.c +++ b/arch/x86/kernel/irqinit.c @@ -97,9 +97,11 @@ void __init native_init_IRQ(void) /* Execute any quirks before the call gates are initialised: */ x86_init.irqs.pre_vector_init(); - if (cpu_feature_enabled(X86_FEATURE_FRED)) + /* FRED's IRQ path may be used even if FRED isn't fully enabled. */ + if (IS_ENABLED(CONFIG_X86_FRED)) fred_complete_exception_setup(); - else + + if (!cpu_feature_enabled(X86_FEATURE_FRED)) idt_setup_apic_and_irq_gates(); lapic_assign_system_vectors(); |