From 479c2a1cb7fb82d23e66eab78b00fc5b0638439b Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Tue, 10 May 2016 18:21:21 +0800 Subject: [PATCH] ioapic: keep RO bits for IOAPIC entry MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently IOAPIC RO bits can be written. To be better aligned with hardware, we should let them read-only. Reviewed-by: Radim Krčmář Signed-off-by: Peter Xu Message-Id: <1462875682-1349-2-git-send-email-peterx@redhat.com> Signed-off-by: Paolo Bonzini --- hw/intc/ioapic.c | 4 ++++ include/hw/i386/ioapic_internal.h | 5 +++++ 2 files changed, 9 insertions(+) diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c index 4f42b911a2..c27ee83722 100644 --- a/hw/intc/ioapic.c +++ b/hw/intc/ioapic.c @@ -281,6 +281,7 @@ ioapic_mem_write(void *opaque, hwaddr addr, uint64_t val, default: index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1; if (index >= 0 && index < IOAPIC_NUM_PINS) { + uint64_t ro_bits = s->ioredtbl[index] & IOAPIC_RO_BITS; if (s->ioregsel & 1) { s->ioredtbl[index] &= 0xffffffff; s->ioredtbl[index] |= (uint64_t)val << 32; @@ -288,6 +289,9 @@ ioapic_mem_write(void *opaque, hwaddr addr, uint64_t val, s->ioredtbl[index] &= ~0xffffffffULL; s->ioredtbl[index] |= val; } + /* restore RO bits */ + s->ioredtbl[index] &= IOAPIC_RW_BITS; + s->ioredtbl[index] |= ro_bits; ioapic_service(s); } } diff --git a/include/hw/i386/ioapic_internal.h b/include/hw/i386/ioapic_internal.h index 797ed47305..cab9e67ee7 100644 --- a/include/hw/i386/ioapic_internal.h +++ b/include/hw/i386/ioapic_internal.h @@ -47,6 +47,11 @@ #define IOAPIC_LVT_DEST_MODE (1 << IOAPIC_LVT_DEST_MODE_SHIFT) #define IOAPIC_LVT_DELIV_MODE (7 << IOAPIC_LVT_DELIV_MODE_SHIFT) +/* Bits that are read-only for IOAPIC entry */ +#define IOAPIC_RO_BITS (IOAPIC_LVT_REMOTE_IRR | \ + IOAPIC_LVT_DELIV_STATUS) +#define IOAPIC_RW_BITS (~(uint64_t)IOAPIC_RO_BITS) + #define IOAPIC_TRIGGER_EDGE 0 #define IOAPIC_TRIGGER_LEVEL 1