From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38355) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TIi0j-0004yy-7t for qemu-devel@nongnu.org; Mon, 01 Oct 2012 11:34:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TIi0d-0004FK-1a for qemu-devel@nongnu.org; Mon, 01 Oct 2012 11:34:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61652) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TIi0c-0004Dm-QC for qemu-devel@nongnu.org; Mon, 01 Oct 2012 11:34:14 -0400 Message-ID: <5069B7F0.30300@redhat.com> Date: Mon, 01 Oct 2012 17:34:08 +0200 From: Pavel Hrdina MIME-Version: 1.0 References: <1347244257-15586-1-git-send-email-david@gibson.dropbear.id.au> <1347244257-15586-3-git-send-email-david@gibson.dropbear.id.au> <504DEAD1.3060908@suse.de> <20120912055706.GX12554@truffula.fritz.box> <50699E11.8020203@redhat.com> <871uhigtb3.fsf@codemonkey.ws> In-Reply-To: <871uhigtb3.fsf@codemonkey.ws> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 2/2] cpu_physical_memory_write_rom() needs to do TB invalidates List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: qemu-devel@nongnu.org, =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= , David Gibson On 10/01/2012 04:28 PM, Anthony Liguori wrote: > Pavel Hrdina writes: > >> On 09/12/2012 07:57 AM, David Gibson wrote: >>> On Mon, Sep 10, 2012 at 03:27:45PM +0200, Andreas F=C3=A4rber wrote: >>>> Am 10.09.2012 04:30, schrieb David Gibson: >>>>> cpu_physical_memory_write_rom(), despite the name, can also be used= to >>>>> write images into RAM - and will often be used that way if the mach= ine >>>>> uses load_image_targphys() into RAM addresses. >>>>> >>>>> However, cpu_physical_memory_write_rom(), unlike cpu_physical_memor= y_rw() >>>>> does invalidate any cached TBs which might be affected by the regio= n >>>> "doesn't"? >>>> >>>> Otherwise doesn't look wrong. >>> Oops, comment updated. >>> >>> From 6b913afaf83f52ee787271827c84b492e8ac5895 Mon Sep 17 00:00:00 2= 001 >>> From: David Gibson >>> Date: Wed, 22 Aug 2012 14:58:04 +1000 >>> Subject: [PATCH] cpu_physical_memory_write_rom() needs to do TB inval= idates >>> >>> cpu_physical_memory_write_rom(), despite the name, can also be used t= o >>> write images into RAM - and will often be used that way if the machin= e >>> uses load_image_targphys() into RAM addresses. >>> >>> However, cpu_physical_memory_write_rom(), unlike >>> cpu_physical_memory_rw() doesn't invalidate any cached TBs which migh= t >>> be affected by the region written. >>> >>> This was breaking reset (under full emu) on the pseries machine - we = loaded >>> our firmware image into RAM, and while executing it rewrite the code = at >>> the entry point (correctly causing a TB invalidate/refresh). When we >>> reset the firmware image was reloaded, but the TB from the rewrite wa= s >>> still active and caused us to get an illegal instruction trap. >>> >>> This patch fixes the bug by duplicating the tb invalidate code from >>> cpu_physical_memory_rw() in cpu_physical_memory_write_rom(). >>> >>> Signed-off-by: David Gibson >>> --- >>> exec.c | 7 +++++++ >>> 1 file changed, 7 insertions(+) >>> >>> diff --git a/exec.c b/exec.c >>> index 5834766..eff40d7 100644 >>> --- a/exec.c >>> +++ b/exec.c >>> @@ -3523,6 +3523,13 @@ void cpu_physical_memory_write_rom(target_phys= _addr_t addr, >>> /* ROM/RAM case */ >>> ptr =3D qemu_get_ram_ptr(addr1); >>> memcpy(ptr, buf, l); >>> + if (!cpu_physical_memory_is_dirty(addr1)) { >>> + /* invalidate code */ >>> + tb_invalidate_phys_page_range(addr1, addr1 + l, 0); >>> + /* set dirty bit */ >>> + cpu_physical_memory_set_dirty_flags( >>> + addr1, (0xff & ~CODE_DIRTY_FLAG)); >>> + } >>> qemu_put_ram_ptr(ptr); >>> } >>> len -=3D l; >> Hi, >> >> this patch breaks Windows XP guest at all. Windows XP boot ends in loo= b >> by restarting itself after time-out expires in windows advanced boot >> options. >> >> I started the guest using this command-line: >> >> ./x86_64-softmmu/qemu-system-x86_64 -m 2G -drive >> file=3D/data/data-shared/images/winxp-test.img -vnc 0.0.0.0:0 > Does changing the tb_invalidate_phys_page_range() call to: > > tb_invalidate_phys_page_range(addr1, addr1 + MAX(l, TARGET_PAGE_SIZE), = 0); > > The dirty flag is being reset for the full page but we're potentially > only invalidating a subset of TBs that occur on the page. > > Regards, > > Anthony Liguori > No, it doesn't fix this bug. Pavel >> Pavel