From b030958c2b5c133e70d083ff8a612cb62254eabc Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 26 Jun 2020 09:22:32 +0200 Subject: [PATCH] s390x/pv: Convert to ram_block_discard_disable() Discarding RAM does not work as expected with protected VMs. Let's switch to ram_block_discard_disable() for now, as we want to get rid of qemu_balloon_inhibit(). Note that it will currently never fail, but might fail in the future with new technologies (e.g., virtio-mem). Acked-by: Cornelia Huck Cc: Richard Henderson Cc: Cornelia Huck Cc: Halil Pasic Cc: Christian Borntraeger Cc: Janosch Frank Signed-off-by: David Hildenbrand Message-Id: <20200626072248.78761-6-david@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/s390x/s390-virtio-ccw.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c index b111406d56..023fd25f2b 100644 --- a/hw/s390x/s390-virtio-ccw.c +++ b/hw/s390x/s390-virtio-ccw.c @@ -43,7 +43,6 @@ #include "hw/qdev-properties.h" #include "hw/s390x/tod.h" #include "sysemu/sysemu.h" -#include "sysemu/balloon.h" #include "hw/s390x/pv.h" #include "migration/blocker.h" @@ -329,7 +328,7 @@ static void s390_machine_unprotect(S390CcwMachineState *ms) ms->pv = false; migrate_del_blocker(pv_mig_blocker); error_free_or_abort(&pv_mig_blocker); - qemu_balloon_inhibit(false); + ram_block_discard_disable(false); } static int s390_machine_protect(S390CcwMachineState *ms) @@ -338,17 +337,22 @@ static int s390_machine_protect(S390CcwMachineState *ms) int rc; /* - * Ballooning on protected VMs needs support in the guest for - * sharing and unsharing balloon pages. Block ballooning for - * now, until we have a solution to make at least Linux guests - * either support it or fail gracefully. + * Discarding of memory in RAM blocks does not work as expected with + * protected VMs. Sharing and unsharing pages would be required. Disable + * it for now, until until we have a solution to make at least Linux + * guests either support it (e.g., virtio-balloon) or fail gracefully. */ - qemu_balloon_inhibit(true); + rc = ram_block_discard_disable(true); + if (rc) { + error_report("protected VMs: cannot disable RAM discard"); + return rc; + } + error_setg(&pv_mig_blocker, "protected VMs are currently not migrateable."); rc = migrate_add_blocker(pv_mig_blocker, &local_err); if (rc) { - qemu_balloon_inhibit(false); + ram_block_discard_disable(false); error_report_err(local_err); error_free_or_abort(&pv_mig_blocker); return rc; @@ -357,7 +361,7 @@ static int s390_machine_protect(S390CcwMachineState *ms) /* Create SE VM */ rc = s390_pv_vm_enable(); if (rc) { - qemu_balloon_inhibit(false); + ram_block_discard_disable(false); migrate_del_blocker(pv_mig_blocker); error_free_or_abort(&pv_mig_blocker); return rc;