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kvm: LAPIC: write down valid APIC registers

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Replace a magic 64-bit mask with a list of valid registers, computing
the same mask in the end.

Suggested-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2019-07-05 14:57:58 +02:00
parent 101628ded5
commit 01402cf810
1 changed files with 31 additions and 11 deletions
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42
arch/x86/kvm/lapic.c
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@ -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;
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);
if ((alignment + len) > 4) {
apic_debug("KVM_APIC_READ: alignment error %x %d\n",
offset, len);
return 1;
}
/* ARBPRI is not valid on x2APIC */
if (!apic_x2apic_mode(apic))
valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI);
/* ARBPRI is also reserved on x2APIC */
if (apic_x2apic_mode(apic))
rmask &= ~(1 << (APIC_ARBPRI >> 4));
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;