From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:34367) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T43wk-0003Mk-Gi for qemu-devel@nongnu.org; Wed, 22 Aug 2012 01:57:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T43wc-0007pr-PA for qemu-devel@nongnu.org; Wed, 22 Aug 2012 01:57:42 -0400 Received: from e23smtp05.au.ibm.com ([202.81.31.147]:39672) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T43wc-0007pE-6t for qemu-devel@nongnu.org; Wed, 22 Aug 2012 01:57:34 -0400 Received: from /spool/local by e23smtp05.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 22 Aug 2012 15:56:47 +1000 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay05.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q7M5mUM526214480 for ; Wed, 22 Aug 2012 15:48:30 +1000 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q7M5vKRn008861 for ; Wed, 22 Aug 2012 15:57:20 +1000 Date: Wed, 22 Aug 2012 15:57:25 +1000 From: David Gibson Message-ID: <20120822055725.GZ29724@truffula.fritz.box> References: <1345611560-8290-1-git-send-email-david@gibson.dropbear.id.au> <48B2B165-8770-4BD9-9D9A-2D089A9A9208@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48B2B165-8770-4BD9-9D9A-2D089A9A9208@suse.de> Subject: Re: [Qemu-devel] [PATCH] cpu_physical_memory_write_rom() needs to do TB invalidates List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org On Wed, Aug 22, 2012 at 07:55:31AM +0200, Alexander Graf wrote: > > On 22.08.2012, at 06:59, David Gibson wrote: > > > 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 machine > > uses load_image_targphys() into RAM addresses. > > > > However, cpu_physical_memory_write_rom(), unlike cpu_physical_memory_rw() > > does invalidate any cached TBs which might 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 was > > 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 = 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)); > > + } > > Can't we just call cpu_physical_memory_rw in the RAM case? The > function only tries to not do MMIO accesses on ROM pages, right? Maybe. It's not clear at all to me what cases cpu_physical_memory_write_rom() is supposed to be for, as opposed to just using cpu_physical_memory_rw(). -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson