From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33036) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XlJMf-00021L-IY for qemu-devel@nongnu.org; Mon, 03 Nov 2014 10:16:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XlJMY-0005VK-1C for qemu-devel@nongnu.org; Mon, 03 Nov 2014 10:16:17 -0500 Received: from e06smtp15.uk.ibm.com ([195.75.94.111]:37619) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XlJMX-0005Up-PD for qemu-devel@nongnu.org; Mon, 03 Nov 2014 10:16:09 -0500 Received: from /spool/local by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 3 Nov 2014 15:16:08 -0000 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Mon, 3 Nov 2014 16:14:50 +0100 Message-Id: <1415027690-9123-1-git-send-email-clg@fr.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] =?utf-8?q?=5BPATCH=5D_target-ppc=3A_explicitly_save_?= =?utf-8?q?page_table_headers_in_big_endian?= List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Alexey Kardashevskiy , qemu-devel@nongnu.org, =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= , Paul Mackerras , qemu-ppc@nongnu.org Currently, when the page tables are saved, the kvm_get_htab_header structs and the ptes are assumed being big endian and dumped as a indistinct blob in the statefile. This is no longer true when the host is little endian and this breaks restoration. This patch unfolds the kvmppc_save_htab routine to write explicitly the kvm_get_htab_header structs in big endian. The ptes are left untouched. Signed-off-by: Cédric Le Goater Cc: Paul Mackerras Cc: Alexey Kardashevskiy Cc: Gregory Kurz --- This patch needs to be completed by a relatively simple modification of kvm_htab_write() in the kvm_hv kernel mmodule. Tested on 3.17-rc7 with LE and BE host, and with a cross endian gdb. target-ppc/kvm.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) Index: qemu.git/target-ppc/kvm.c =================================================================== --- qemu.git.orig/target-ppc/kvm.c +++ qemu.git/target-ppc/kvm.c @@ -2246,8 +2246,23 @@ int kvmppc_save_htab(QEMUFile *f, int fd strerror(errno)); return rc; } else if (rc) { - /* Kernel already retuns data in BE format for the file */ - qemu_put_buffer(f, buf, rc); + uint8_t *buffer = buf; + ssize_t n = rc; + while (n) { + struct kvm_get_htab_header *head = + (struct kvm_get_htab_header *) buffer; + size_t chunksize = sizeof(*head) + + HASH_PTE_SIZE_64 * head->n_valid; + + qemu_put_be32(f, head->index); + qemu_put_be16(f, head->n_valid); + qemu_put_be16(f, head->n_invalid); + qemu_put_buffer(f, (void *)(head + 1), + HASH_PTE_SIZE_64 * head->n_valid); + + buffer += chunksize; + n -= chunksize; + } } } while ((rc != 0) && ((max_ns < 0) @@ -2264,7 +2279,6 @@ int kvmppc_load_htab_chunk(QEMUFile *f, ssize_t rc; buf = alloca(chunksize); - /* This is KVM on ppc, so this is all big-endian */ buf->index = index; buf->n_valid = n_valid; buf->n_invalid = n_invalid;