Commit 01402cf8 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

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: default avatarLiran Alon <liran.alon@oracle.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 101628de

arch/x86/kvm/lapic.c

+32 −12
Original line number Diff line number Diff line
@@ -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;