Commit a028edea authored by Alexander Bulekov's avatar Alexander Bulekov Committed by Stefan Hajnoczi
Browse files

exec: keep ram block across fork when using qtest 



Ram blocks were marked MADV_DONTFORK breaking fuzzing-tests which
execute each test-input in a forked process.

Signed-off-by: default avatarAlexander Bulekov <alxndr@bu.edu>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarDarren Kenny <darren.kenny@oracle.com>
Message-id: 20200220041118.23264-14-alxndr@bu.edu
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 5f6fd09a

exec.c

+10 −2
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
#include "sysemu/kvm.h"

#include "sysemu/sysemu.h"

#include "sysemu/tcg.h"

#include "sysemu/qtest.h"

#include "qemu/timer.h"

#include "qemu/config-file.h"

#include "qemu/error-report.h"
@@ -2305,8 +2306,15 @@ static void ram_block_add(RAMBlock *new_block, Error **errp, bool shared) 
    if (new_block->host) {

        qemu_ram_setup_dump(new_block->host, new_block->max_length);

        qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_HUGEPAGE);

        /* MADV_DONTFORK is also needed by KVM in absence of synchronous MMU */

        qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_DONTFORK);

        /*

         * MADV_DONTFORK is also needed by KVM in absence of synchronous MMU

         * Configure it unless the machine is a qtest server, in which case

         * KVM is not used and it may be forked (eg for fuzzing purposes).

         */

        if (!qtest_enabled()) {

            qemu_madvise(new_block->host, new_block->max_length,

                         QEMU_MADV_DONTFORK);

        }

        ram_block_notify_add(new_block->host, new_block->max_length);

    }

}