From 01402cf81051f796dac7c60ca11d6147153ca46a Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 5 Jul 2019 14:57:58 +0200 Subject: [PATCH] kvm: LAPIC: write down valid APIC registers Replace a magic 64-bit mask with a list of valid registers, computing the same mask in the end. Suggested-by: Liran Alon Signed-off-by: Paolo Bonzini --- arch/x86/kvm/lapic.c | 44 ++++++++++++++++++++++++++++++++------------ 1 file changed, 32 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 2e4470f..e4227ce 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1312,25 +1312,45 @@ static inline struct kvm_lapic *to_lapic(struct kvm_io_device *dev) return container_of(dev, struct kvm_lapic, dev); } +#define APIC_REG_MASK(reg) (1ull << ((reg) >> 4)) +#define APIC_REGS_MASK(first, count) \ + (APIC_REG_MASK(first) * ((1ull << (count)) - 1)) + int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, void *data) { unsigned char alignment = offset & 0xf; u32 result; /* this bitmask has a bit cleared for each reserved register */ - u64 rmask = 0x43ff01ffffffe70cULL; - - if ((alignment + len) > 4) { - apic_debug("KVM_APIC_READ: alignment error %x %d\n", - offset, len); - return 1; - } - - /* ARBPRI is also reserved on x2APIC */ - if (apic_x2apic_mode(apic)) - rmask &= ~(1 << (APIC_ARBPRI >> 4)); + u64 valid_reg_mask = + APIC_REG_MASK(APIC_ID) | + APIC_REG_MASK(APIC_LVR) | + APIC_REG_MASK(APIC_TASKPRI) | + APIC_REG_MASK(APIC_PROCPRI) | + APIC_REG_MASK(APIC_LDR) | + APIC_REG_MASK(APIC_DFR) | + APIC_REG_MASK(APIC_SPIV) | + APIC_REGS_MASK(APIC_ISR, APIC_ISR_NR) | + APIC_REGS_MASK(APIC_TMR, APIC_ISR_NR) | + APIC_REGS_MASK(APIC_IRR, APIC_ISR_NR) | + APIC_REG_MASK(APIC_ESR) | + APIC_REG_MASK(APIC_ICR) | + APIC_REG_MASK(APIC_ICR2) | + APIC_REG_MASK(APIC_LVTT) | + APIC_REG_MASK(APIC_LVTTHMR) | + APIC_REG_MASK(APIC_LVTPC) | + APIC_REG_MASK(APIC_LVT0) | + APIC_REG_MASK(APIC_LVT1) | + APIC_REG_MASK(APIC_LVTERR) | + APIC_REG_MASK(APIC_TMICT) | + APIC_REG_MASK(APIC_TMCCT) | + APIC_REG_MASK(APIC_TDCR); + + /* ARBPRI is not valid on x2APIC */ + if (!apic_x2apic_mode(apic)) + valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI); - if (offset > 0x3f0 || !(rmask & (1ULL << (offset >> 4)))) { + if (offset > 0x3f0 || !(valid_reg_mask & APIC_REG_MASK(offset))) { apic_debug("KVM_APIC_READ: read reserved register %x\n", offset); return 1; -- 2.7.4