From 5770fe43fe1e15e6f53cfd3705605e8645b95a98 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Fri, 13 Mar 2020 17:17:08 +0000 Subject: [PATCH 20/20] exec/rom_reset: Free rom data during inmigrate skip MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Dr. David Alan Gilbert Message-id: <20200313171708.242774-1-dgilbert@redhat.com> Patchwork-id: 94292 O-Subject: [RHEL-AV-8.2.0 qemu-kvm PATCH 1/1] exec/rom_reset: Free rom data during inmigrate skip Bugzilla: 1809380 RH-Acked-by: Daniel P. Berrange RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Paolo Bonzini From: "Dr. David Alan Gilbert" bz: https://bugzilla.redhat.com/show_bug.cgi?id=1809380 brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=27249921 branch: rhel-av-8.2.0 upstream: Posted and with review-by, not merged yet Commit 355477f8c73e9 skips rom reset when we're an incoming migration so as not to overwrite shared ram in the ignore-shared migration optimisation. However, it's got an unexpected side effect that because it skips freeing the ROM data, when rom_reset gets called later on, after migration (e.g. during a reboot), the ROM does get reset to the original file contents. Because of seabios/x86's weird reboot process this confuses a reboot into hanging after a migration. Fixes: 355477f8c73e9 ("migration: do not rom_reset() during incoming migration") https://bugzilla.redhat.com/show_bug.cgi?id=1809380 Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Danilo C. L. de Paula --- hw/core/loader.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/hw/core/loader.c b/hw/core/loader.c index 5099f27..375b29b 100644 --- a/hw/core/loader.c +++ b/hw/core/loader.c @@ -1118,19 +1118,26 @@ static void rom_reset(void *unused) { Rom *rom; - /* - * We don't need to fill in the RAM with ROM data because we'll fill - * the data in during the next incoming migration in all cases. Note - * that some of those RAMs can actually be modified by the guest on ARM - * so this is probably the only right thing to do here. - */ - if (runstate_check(RUN_STATE_INMIGRATE)) - return; - QTAILQ_FOREACH(rom, &roms, next) { if (rom->fw_file) { continue; } + /* + * We don't need to fill in the RAM with ROM data because we'll fill + * the data in during the next incoming migration in all cases. Note + * that some of those RAMs can actually be modified by the guest. + */ + if (runstate_check(RUN_STATE_INMIGRATE)) { + if (rom->data && rom->isrom) { + /* + * Free it so that a rom_reset after migration doesn't + * overwrite a potentially modified 'rom'. + */ + rom_free_data(rom); + } + continue; + } + if (rom->data == NULL) { continue; } -- 1.8.3.1