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| author | Julian Stecklina <js@alien8.de> | 2011-11-23 13:54:30 +0100 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-12-27 11:17:44 +0200 |
| commit | d77fe6354d5b67f4d4eb62a47621da2b3ee3539e (patch) | |
| tree | 4c399e8125d69d128c200807eb517dd7c20b277b /virt/kvm/ioapic.c | |
| parent | 60f9a9ef5492cae66aca2ad9873360161320d5af (diff) | |
| download | lwn-d77fe6354d5b67f4d4eb62a47621da2b3ee3539e.tar.gz lwn-d77fe6354d5b67f4d4eb62a47621da2b3ee3539e.zip | |
KVM: Allow aligned byte and word writes to IOAPIC registers.
This fixes byte accesses to IOAPIC_REG_SELECT as mandated by at least the
ICH10 and Intel Series 5 chipset specs. It also makes ioapic_mmio_write
consistent with ioapic_mmio_read, which also allows byte and word accesses.
Signed-off-by: Julian Stecklina <js@alien8.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt/kvm/ioapic.c')
| -rw-r--r-- | virt/kvm/ioapic.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 3eed61eb4867..71e2253edee7 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -332,9 +332,18 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len, (void*)addr, len, val); ASSERT(!(addr & 0xf)); /* check alignment */ - if (len == 4 || len == 8) + switch (len) { + case 8: + case 4: data = *(u32 *) val; - else { + break; + case 2: + data = *(u16 *) val; + break; + case 1: + data = *(u8 *) val; + break; + default: printk(KERN_WARNING "ioapic: Unsupported size %d\n", len); return 0; } @@ -343,7 +352,7 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len, spin_lock(&ioapic->lock); switch (addr) { case IOAPIC_REG_SELECT: - ioapic->ioregsel = data; + ioapic->ioregsel = data & 0xFF; /* 8-bit register */ break; case IOAPIC_REG_WINDOW: |