On 03/18/2012 06:12 PM, malc wrote:
> 97161e177b4ea2730dff13c4df01475762ab6048 broke booting of a DOS image
> i've been using for years, the VM stalls at "Booting from hard disk"
> BIOS message never making any progress.
Can you post an image that exhibits the problem?
Also, try the attached patch.
--
error compiling committee.c: too many arguments to function
>From bb363db2608dfc9b49b53994dc20d68169e66774 Mon Sep 17 00:00:00 2001
From: Avi Kivity <a...@redhat.com>
Date: Wed, 14 Mar 2012 16:19:39 +0200
Subject: [PATCH] exec: fix write tlb entry misused as iotlb
A couple of code paths check the lower bits of CPUTLBEntry::addr_write
against io_mem_ram as a way of looking for a dirty RAM page. This works
by accident since the value is zero, which matches all clear bits for
TLB_INVALID, TLB_MMIO, and TLB_NOTDIRTY (indicating dirty RAM).
Make it work by design by checking for the proper bits.
Signed-off-by: Avi Kivity <a...@redhat.com>
---
exec.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/exec.c b/exec.c
index 8fd50a1..d8b089e 100644
--- a/exec.c
+++ b/exec.c
@@ -2031,14 +2031,19 @@ static void tlb_unprotect_code_phys(CPUArchState *env, ram_addr_t ram_addr,
cpu_physical_memory_set_dirty_flags(ram_addr, CODE_DIRTY_FLAG);
}
+static bool tlb_is_dirty_ram(CPUTLBEntry *tlbe)
+{
+ return (tlbe->addr_write & (TLB_INVALID_MASK|TLB_MMIO|TLB_NOTDIRTY)) == 0;
+}
+
static inline void tlb_reset_dirty_range(CPUTLBEntry *tlb_entry,
unsigned long start, unsigned long length)
{
unsigned long addr;
- if ((tlb_entry->addr_write & ~TARGET_PAGE_MASK) == io_mem_ram.ram_addr) {
+ if (tlb_is_dirty_ram(tlb_entry)) {
addr = (tlb_entry->addr_write & TARGET_PAGE_MASK) + tlb_entry->addend;
if ((addr - start) < length) {
- tlb_entry->addr_write = (tlb_entry->addr_write & TARGET_PAGE_MASK) | TLB_NOTDIRTY;
+ tlb_entry->addr_write |= TLB_NOTDIRTY;
}
}
}
@@ -2091,7 +2096,7 @@ static inline void tlb_update_dirty(CPUTLBEntry *tlb_entry)
ram_addr_t ram_addr;
void *p;
- if ((tlb_entry->addr_write & ~TARGET_PAGE_MASK) == io_mem_ram.ram_addr) {
+ if (tlb_is_dirty_ram(tlb_entry)) {
p = (void *)(unsigned long)((tlb_entry->addr_write & TARGET_PAGE_MASK)
+ tlb_entry->addend);
ram_addr = qemu_ram_addr_from_host_nofail(p);
--
1.7.9
