Re: [Qemu-devel] [PATCH] qemu-kvm: fix unmatched RAM alloction/free

[Paolo Bonzini <pbonzini@redhat.com>]

> mmap is used in qemu_vmalloc function instead of qemu_memalign(commit
> 7dda5dc8), so it should change qemu_vfree to munmap to fix a unmatched
> issue.
> 
> This issue appears when a PCI device is being assigned to KVM guest,
> failure to read PCI rom file will bring RAM free, then the incorrect
> qemu_vfree calling will cause a segment fault.
> 
> Signed-off-by: Xudong Hao <xudong.hao@intel.com>
> ---
>  exec.c |    6 +-----
>  1 files changed, 1 insertions(+), 5 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index fa1e0c3..d40d237 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1152,15 +1152,11 @@ void qemu_ram_free(ram_addr_t addr)
>                  abort();
>  #endif
>              } else {
> -#if defined(TARGET_S390X) && defined(CONFIG_KVM)
> -                munmap(block->host, block->length);
> -#else
>                  if (xen_enabled()) {
>                      xen_invalidate_map_cache_entry(block->host);
>                  } else {
> -                    qemu_vfree(block->host);
> +                    munmap(block->host, block->length);
>                  }
> -#endif
>              }
>              g_free(block);
>              break;

Just "git pull". :)  This is very similar to commit e7a09b9 (osdep: introduce
qemu_anon_ram_free to free qemu_anon_ram_alloc-ed memory, 2013-05-13)

Paolo