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[RFC PATCH v1 24/25] hw/xen: Implement soft reset for emulated gnttab
From: |
David Woodhouse |
Subject: |
[RFC PATCH v1 24/25] hw/xen: Implement soft reset for emulated gnttab |
Date: |
Thu, 2 Mar 2023 15:34:34 +0000 |
From: David Woodhouse <dwmw@amazon.co.uk>
This is only part of it; we will also need to get the PV back end drivers
to tear down their own mappings (or do it for them, but they kind of need
to stop using the pointers too).
Some more work on the actual PV back ends and xen-bus code is going to be
needed to really make soft reset and migration fully functional, and this
part is the basis for that.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
hw/i386/kvm/xen_gnttab.c | 26 ++++++++++++++++++++++++--
hw/i386/kvm/xen_gnttab.h | 1 +
target/i386/kvm/xen-emu.c | 5 +++++
3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/hw/i386/kvm/xen_gnttab.c b/hw/i386/kvm/xen_gnttab.c
index 2bf91d36c0..21c30e3659 100644
--- a/hw/i386/kvm/xen_gnttab.c
+++ b/hw/i386/kvm/xen_gnttab.c
@@ -72,13 +72,11 @@ static void xen_gnttab_realize(DeviceState *dev, Error
**errp)
error_setg(errp, "Xen grant table support is for Xen emulation");
return;
}
- s->nr_frames = 0;
s->max_frames = kvm_xen_get_gnttab_max_frames();
memory_region_init_ram(&s->gnt_frames, OBJECT(dev), "xen:grant_table",
XEN_PAGE_SIZE * s->max_frames, &error_abort);
memory_region_set_enabled(&s->gnt_frames, true);
s->entries.v1 = memory_region_get_ram_ptr(&s->gnt_frames);
- memset(s->entries.v1, 0, XEN_PAGE_SIZE * s->max_frames);
/* Create individual page-sizes aliases for overlays */
s->gnt_aliases = (void *)g_new0(MemoryRegion, s->max_frames);
@@ -90,8 +88,11 @@ static void xen_gnttab_realize(DeviceState *dev, Error
**errp)
s->gnt_frame_gpas[i] = INVALID_GPA;
}
+ s->nr_frames = 0;
+ memset(s->entries.v1, 0, XEN_PAGE_SIZE * s->max_frames);
s->entries.v1[GNTTAB_RESERVED_XENSTORE].flags = GTF_permit_access;
s->entries.v1[GNTTAB_RESERVED_XENSTORE].frame = XEN_SPECIAL_PFN(XENSTORE);
+
qemu_mutex_init(&s->gnt_lock);
xen_gnttab_singleton = s;
@@ -523,3 +524,24 @@ static struct gnttab_backend_ops emu_gnttab_backend_ops = {
.unmap = xen_be_gnttab_unmap,
};
+int xen_gnttab_reset(void)
+{
+ XenGnttabState *s = xen_gnttab_singleton;
+
+ if (!s) {
+ return -ENOTSUP;
+ }
+
+ QEMU_LOCK_GUARD(&s->gnt_lock);
+
+ s->nr_frames = 0;
+
+ memset(s->entries.v1, 0, XEN_PAGE_SIZE * s->max_frames);
+
+ s->entries.v1[GNTTAB_RESERVED_XENSTORE].flags = GTF_permit_access;
+ s->entries.v1[GNTTAB_RESERVED_XENSTORE].frame = XEN_SPECIAL_PFN(XENSTORE);
+
+ memset(s->map_track, 0, s->max_frames * ENTRIES_PER_FRAME_V1);
+
+ return 0;
+}
diff --git a/hw/i386/kvm/xen_gnttab.h b/hw/i386/kvm/xen_gnttab.h
index 3bdbe96191..ee215239b0 100644
--- a/hw/i386/kvm/xen_gnttab.h
+++ b/hw/i386/kvm/xen_gnttab.h
@@ -13,6 +13,7 @@
#define QEMU_XEN_GNTTAB_H
void xen_gnttab_create(void);
+int xen_gnttab_reset(void);
int xen_gnttab_map_page(uint64_t idx, uint64_t gfn);
struct gnttab_set_version;
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index bad3131d08..0bb6c601c9 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -1406,6 +1406,11 @@ int kvm_xen_soft_reset(void)
return err;
}
+ err = xen_gnttab_reset();
+ if (err) {
+ return err;
+ }
+
err = xen_xenstore_reset();
if (err) {
return err;
--
2.39.0
- [RFC PATCH v1 10/25] hw/xen: Add gnttab operations to allow redirection to internal emulation, (continued)
- [RFC PATCH v1 10/25] hw/xen: Add gnttab operations to allow redirection to internal emulation, David Woodhouse, 2023/03/02
- [RFC PATCH v1 23/25] hw/xen: Map guest XENSTORE_PFN grant in emulated Xenstore, David Woodhouse, 2023/03/02
- [RFC PATCH v1 25/25] i386/xen: Initialize Xen backends from pc_basic_device_init() for emulation, David Woodhouse, 2023/03/02
- [RFC PATCH v1 04/25] hw/xen: Implement XenStore transactions, David Woodhouse, 2023/03/02
- [RFC PATCH v1 06/25] hw/xen: Implement XenStore permissions, David Woodhouse, 2023/03/02
- [RFC PATCH v1 24/25] hw/xen: Implement soft reset for emulated gnttab,
David Woodhouse <=
- [RFC PATCH v1 12/25] hw/xen: Add foreignmem operations to allow redirection to internal emulation, David Woodhouse, 2023/03/02
- [RFC PATCH v1 05/25] hw/xen: Watches on XenStore transactions, David Woodhouse, 2023/03/02
- [RFC PATCH v1 18/25] hw/xen: Avoid crash when backend watch fires too early, David Woodhouse, 2023/03/02