qemu-patch-raspberry4/include/hw/ppc/spapr_ovec.h
Greg Kurz 73598c75df spapr: Improve handling of memory unplug with old guests
Since commit 1e8b5b1aa1 ("spapr: Allow memory unplug to always succeed")
trying to unplug memory from a guest that doesn't support it (eg. rhel6)
no longer generates an error like it used to. Instead, it leaves the
memory around : only a subsequent reboot or manual use of drmgr within
the guest can complete the hot-unplug sequence. A flag was added to
SpaprMachineClass so that this new behavior only applies to the default
machine type.

We can do better. CAS processes all pending hot-unplug requests. This
means that we don't really care about what the guest supports if
the hot-unplug request happens before CAS.

All guests that we care for, even old ones, set enough bits in OV5
that lead to a non-empty bitmap in spapr->ov5_cas. Use that as a
heuristic to decide if CAS has already occured or not.

Always accept unplug requests that happen before CAS since CAS will
process them. Restore the previous behavior of rejecting them after
CAS when we know that the guest doesn't support memory hot-unplug.

This behavior is suitable for all machine types : this allows to
drop the pre_6_0_memory_unplug flag.

Fixes: 1e8b5b1aa1 ("spapr: Allow memory unplug to always succeed")
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <161012708715.801107.11418801796987916516.stgit@bahia.lan>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-01-19 10:20:29 +11:00

83 lines
3.1 KiB
C

/*
* QEMU SPAPR Option/Architecture Vector Definitions
*
* Each architecture option is organized/documented by the following
* in LoPAPR 1.1, Table 244:
*
* <vector number>: the bit-vector in which the option is located
* <vector byte>: the byte offset of the vector entry
* <vector bit>: the bit offset within the vector entry
*
* where each vector entry can be one or more bytes.
*
* Firmware expects a somewhat literal encoding of this bit-vector
* structure, where each entry is stored in little-endian so that the
* byte ordering reflects that of the documentation, but where each bit
* offset is from "left-to-right" in the traditional representation of
* a byte value where the MSB is the left-most bit. Thus, each
* individual byte encodes the option bits in reverse order of the
* documented bit.
*
* These definitions/helpers attempt to abstract away this internal
* representation so that we can define/set/test for individual option
* bits using only the documented values. This is done mainly by relying
* on a bitmap to approximate the documented "bit-vector" structure and
* handling conversations to-from the internal representation under the
* covers.
*
* Copyright IBM Corp. 2016
*
* Authors:
* Michael Roth <mdroth@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef SPAPR_OVEC_H
#define SPAPR_OVEC_H
#include "cpu.h"
typedef struct SpaprOptionVector SpaprOptionVector;
#define OV_BIT(byte, bit) ((byte - 1) * BITS_PER_BYTE + bit)
/* option vector 1 */
#define OV1_PPC_3_00 OV_BIT(3, 0) /* guest supports PowerPC 3.00? */
/* option vector 5 */
#define OV5_DRCONF_MEMORY OV_BIT(2, 2)
#define OV5_FORM1_AFFINITY OV_BIT(5, 0)
#define OV5_HP_EVT OV_BIT(6, 5)
#define OV5_HPT_RESIZE OV_BIT(6, 7)
#define OV5_DRMEM_V2 OV_BIT(22, 0)
#define OV5_XIVE_BOTH OV_BIT(23, 0)
#define OV5_XIVE_EXPLOIT OV_BIT(23, 1) /* 1=exploitation 0=legacy */
/* ISA 3.00 MMU features: */
#define OV5_MMU_BOTH OV_BIT(24, 0) /* Radix and hash */
#define OV5_MMU_RADIX_300 OV_BIT(24, 1) /* 1=Radix only, 0=Hash only */
#define OV5_MMU_RADIX_GTSE OV_BIT(26, 1) /* Radix GTSE */
/* interfaces */
SpaprOptionVector *spapr_ovec_new(void);
SpaprOptionVector *spapr_ovec_clone(SpaprOptionVector *ov_orig);
void spapr_ovec_intersect(SpaprOptionVector *ov,
SpaprOptionVector *ov1,
SpaprOptionVector *ov2);
bool spapr_ovec_subset(SpaprOptionVector *ov1, SpaprOptionVector *ov2);
void spapr_ovec_cleanup(SpaprOptionVector *ov);
void spapr_ovec_set(SpaprOptionVector *ov, long bitnr);
void spapr_ovec_clear(SpaprOptionVector *ov, long bitnr);
bool spapr_ovec_test(SpaprOptionVector *ov, long bitnr);
bool spapr_ovec_empty(SpaprOptionVector *ov);
SpaprOptionVector *spapr_ovec_parse_vector(target_ulong table_addr, int vector);
int spapr_dt_ovec(void *fdt, int fdt_offset,
SpaprOptionVector *ov, const char *name);
/* migration */
extern const VMStateDescription vmstate_spapr_ovec;
#endif /* SPAPR_OVEC_H */