From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35434) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1byj0O-0006Wm-OW for qemu-devel@nongnu.org; Mon, 24 Oct 2016 13:25:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1byj0M-0007XE-RJ for qemu-devel@nongnu.org; Mon, 24 Oct 2016 13:25:48 -0400 Received: from orth.archaic.org.uk ([2001:8b0:1d0::2]:47423) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1byj0M-0007Rd-HL for qemu-devel@nongnu.org; Mon, 24 Oct 2016 13:25:46 -0400 Received: from pm215 by orth.archaic.org.uk with local (Exim 4.84_2) (envelope-from ) id 1byj07-0002JB-Bq for qemu-devel@nongnu.org; Mon, 24 Oct 2016 18:25:31 +0100 From: Peter Maydell Date: Mon, 24 Oct 2016 18:25:01 +0100 Message-Id: <1477329928-26414-6-git-send-email-peter.maydell@linaro.org> In-Reply-To: <1477329928-26414-1-git-send-email-peter.maydell@linaro.org> References: <1477329928-26414-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PULL 05/32] migration/savevm.c: migrate non-default page size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Add a subsection to vmstate_configuration which is present only if the guest is using a target page size which is different from the default. This allows us to helpfully diagnose attempts to migrate between machines which are using different target page sizes. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson --- migration/savevm.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/migration/savevm.c b/migration/savevm.c index a831ec2..cfcbbd0 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -265,6 +265,7 @@ typedef struct SaveState { bool skip_configuration; uint32_t len; const char *name; + uint32_t target_page_bits; } SaveState; static SaveState savevm_state = { @@ -286,6 +287,19 @@ static void configuration_pre_save(void *opaque) state->len = strlen(current_name); state->name = current_name; + state->target_page_bits = TARGET_PAGE_BITS; +} + +static int configuration_pre_load(void *opaque) +{ + SaveState *state = opaque; + + /* If there is no target-page-bits subsection it means the source + * predates the variable-target-page-bits support and is using the + * minimum possible value for this CPU. + */ + state->target_page_bits = TARGET_PAGE_BITS_MIN; + return 0; } static int configuration_post_load(void *opaque, int version_id) @@ -298,12 +312,43 @@ static int configuration_post_load(void *opaque, int version_id) (int) state->len, state->name, current_name); return -EINVAL; } + + if (state->target_page_bits != TARGET_PAGE_BITS) { + error_report("Received TARGET_PAGE_BITS is %d but local is %d", + state->target_page_bits, TARGET_PAGE_BITS); + return -EINVAL; + } + return 0; } +/* The target-page-bits subsection is present only if the + * target page size is not the same as the default (ie the + * minimum page size for a variable-page-size guest CPU). + * If it is present then it contains the actual target page + * bits for the machine, and migration will fail if the + * two ends don't agree about it. + */ +static bool vmstate_target_page_bits_needed(void *opaque) +{ + return TARGET_PAGE_BITS > TARGET_PAGE_BITS_MIN; +} + +static const VMStateDescription vmstate_target_page_bits = { + .name = "configuration/target-page-bits", + .version_id = 1, + .minimum_version_id = 1, + .needed = vmstate_target_page_bits_needed, + .fields = (VMStateField[]) { + VMSTATE_UINT32(target_page_bits, SaveState), + VMSTATE_END_OF_LIST() + } +}; + static const VMStateDescription vmstate_configuration = { .name = "configuration", .version_id = 1, + .pre_load = configuration_pre_load, .post_load = configuration_post_load, .pre_save = configuration_pre_save, .fields = (VMStateField[]) { @@ -311,6 +356,10 @@ static const VMStateDescription vmstate_configuration = { VMSTATE_VBUFFER_ALLOC_UINT32(name, SaveState, 0, NULL, 0, len), VMSTATE_END_OF_LIST() }, + .subsections = (const VMStateDescription*[]) { + &vmstate_target_page_bits, + NULL + } }; static void dump_vmstate_vmsd(FILE *out_file, -- 2.7.4