From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- sound/firewire/cmp.c | 351 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 351 insertions(+) create mode 100644 sound/firewire/cmp.c (limited to 'sound/firewire/cmp.c') diff --git a/sound/firewire/cmp.c b/sound/firewire/cmp.c new file mode 100644 index 000000000..b2b76c7c7 --- /dev/null +++ b/sound/firewire/cmp.c @@ -0,0 +1,351 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Connection Management Procedures (IEC 61883-1) helper functions + * + * Copyright (c) Clemens Ladisch + */ + +#include +#include +#include +#include +#include +#include "lib.h" +#include "iso-resources.h" +#include "cmp.h" + +/* MPR common fields */ +#define MPR_SPEED_MASK 0xc0000000 +#define MPR_SPEED_SHIFT 30 +#define MPR_XSPEED_MASK 0x00000060 +#define MPR_XSPEED_SHIFT 5 +#define MPR_PLUGS_MASK 0x0000001f + +/* PCR common fields */ +#define PCR_ONLINE 0x80000000 +#define PCR_BCAST_CONN 0x40000000 +#define PCR_P2P_CONN_MASK 0x3f000000 +#define PCR_P2P_CONN_SHIFT 24 +#define PCR_CHANNEL_MASK 0x003f0000 +#define PCR_CHANNEL_SHIFT 16 + +/* oPCR specific fields */ +#define OPCR_XSPEED_MASK 0x00C00000 +#define OPCR_XSPEED_SHIFT 22 +#define OPCR_SPEED_MASK 0x0000C000 +#define OPCR_SPEED_SHIFT 14 +#define OPCR_OVERHEAD_ID_MASK 0x00003C00 +#define OPCR_OVERHEAD_ID_SHIFT 10 + +enum bus_reset_handling { + ABORT_ON_BUS_RESET, + SUCCEED_ON_BUS_RESET, +}; + +static __printf(2, 3) +void cmp_error(struct cmp_connection *c, const char *fmt, ...) +{ + va_list va; + + va_start(va, fmt); + dev_err(&c->resources.unit->device, "%cPCR%u: %pV", + (c->direction == CMP_INPUT) ? 'i' : 'o', + c->pcr_index, &(struct va_format){ fmt, &va }); + va_end(va); +} + +static u64 mpr_address(struct cmp_connection *c) +{ + if (c->direction == CMP_INPUT) + return CSR_REGISTER_BASE + CSR_IMPR; + else + return CSR_REGISTER_BASE + CSR_OMPR; +} + +static u64 pcr_address(struct cmp_connection *c) +{ + if (c->direction == CMP_INPUT) + return CSR_REGISTER_BASE + CSR_IPCR(c->pcr_index); + else + return CSR_REGISTER_BASE + CSR_OPCR(c->pcr_index); +} + +static int pcr_modify(struct cmp_connection *c, + __be32 (*modify)(struct cmp_connection *c, __be32 old), + int (*check)(struct cmp_connection *c, __be32 pcr), + enum bus_reset_handling bus_reset_handling) +{ + __be32 old_arg, buffer[2]; + int err; + + buffer[0] = c->last_pcr_value; + for (;;) { + old_arg = buffer[0]; + buffer[1] = modify(c, buffer[0]); + + err = snd_fw_transaction( + c->resources.unit, TCODE_LOCK_COMPARE_SWAP, + pcr_address(c), buffer, 8, + FW_FIXED_GENERATION | c->resources.generation); + + if (err < 0) { + if (err == -EAGAIN && + bus_reset_handling == SUCCEED_ON_BUS_RESET) + err = 0; + return err; + } + + if (buffer[0] == old_arg) /* success? */ + break; + + if (check) { + err = check(c, buffer[0]); + if (err < 0) + return err; + } + } + c->last_pcr_value = buffer[1]; + + return 0; +} + + +/** + * cmp_connection_init - initializes a connection manager + * @c: the connection manager to initialize + * @unit: a unit of the target device + * @direction: input or output + * @pcr_index: the index of the iPCR/oPCR on the target device + */ +int cmp_connection_init(struct cmp_connection *c, + struct fw_unit *unit, + enum cmp_direction direction, + unsigned int pcr_index) +{ + __be32 mpr_be; + u32 mpr; + int err; + + c->direction = direction; + err = snd_fw_transaction(unit, TCODE_READ_QUADLET_REQUEST, + mpr_address(c), &mpr_be, 4, 0); + if (err < 0) + return err; + mpr = be32_to_cpu(mpr_be); + + if (pcr_index >= (mpr & MPR_PLUGS_MASK)) + return -EINVAL; + + err = fw_iso_resources_init(&c->resources, unit); + if (err < 0) + return err; + + c->connected = false; + mutex_init(&c->mutex); + c->last_pcr_value = cpu_to_be32(0x80000000); + c->pcr_index = pcr_index; + c->max_speed = (mpr & MPR_SPEED_MASK) >> MPR_SPEED_SHIFT; + if (c->max_speed == SCODE_BETA) + c->max_speed += (mpr & MPR_XSPEED_MASK) >> MPR_XSPEED_SHIFT; + + return 0; +} +EXPORT_SYMBOL(cmp_connection_init); + +/** + * cmp_connection_check_used - check connection is already esablished or not + * @c: the connection manager to be checked + * @used: the pointer to store the result of checking the connection + */ +int cmp_connection_check_used(struct cmp_connection *c, bool *used) +{ + __be32 pcr; + int err; + + err = snd_fw_transaction( + c->resources.unit, TCODE_READ_QUADLET_REQUEST, + pcr_address(c), &pcr, 4, 0); + if (err >= 0) + *used = !!(pcr & cpu_to_be32(PCR_BCAST_CONN | + PCR_P2P_CONN_MASK)); + + return err; +} +EXPORT_SYMBOL(cmp_connection_check_used); + +/** + * cmp_connection_destroy - free connection manager resources + * @c: the connection manager + */ +void cmp_connection_destroy(struct cmp_connection *c) +{ + WARN_ON(c->connected); + mutex_destroy(&c->mutex); + fw_iso_resources_destroy(&c->resources); +} +EXPORT_SYMBOL(cmp_connection_destroy); + +int cmp_connection_reserve(struct cmp_connection *c, + unsigned int max_payload_bytes) +{ + guard(mutex)(&c->mutex); + + if (WARN_ON(c->resources.allocated)) + return -EBUSY; + + c->speed = min(c->max_speed, + fw_parent_device(c->resources.unit)->max_speed); + + return fw_iso_resources_allocate(&c->resources, max_payload_bytes, + c->speed); +} +EXPORT_SYMBOL(cmp_connection_reserve); + +void cmp_connection_release(struct cmp_connection *c) +{ + guard(mutex)(&c->mutex); + fw_iso_resources_free(&c->resources); +} +EXPORT_SYMBOL(cmp_connection_release); + +static __be32 ipcr_set_modify(struct cmp_connection *c, __be32 ipcr) +{ + ipcr &= ~cpu_to_be32(PCR_BCAST_CONN | + PCR_P2P_CONN_MASK | + PCR_CHANNEL_MASK); + ipcr |= cpu_to_be32(1 << PCR_P2P_CONN_SHIFT); + ipcr |= cpu_to_be32(c->resources.channel << PCR_CHANNEL_SHIFT); + + return ipcr; +} + +static int get_overhead_id(struct cmp_connection *c) +{ + int id; + + /* + * apply "oPCR overhead ID encoding" + * the encoding table can convert up to 512. + * here the value over 512 is converted as the same way as 512. + */ + for (id = 1; id < 16; id++) { + if (c->resources.bandwidth_overhead < (id << 5)) + break; + } + if (id == 16) + id = 0; + + return id; +} + +static __be32 opcr_set_modify(struct cmp_connection *c, __be32 opcr) +{ + unsigned int spd, xspd; + + /* generate speed and extended speed field value */ + if (c->speed > SCODE_400) { + spd = SCODE_800; + xspd = c->speed - SCODE_800; + } else { + spd = c->speed; + xspd = 0; + } + + opcr &= ~cpu_to_be32(PCR_BCAST_CONN | + PCR_P2P_CONN_MASK | + OPCR_XSPEED_MASK | + PCR_CHANNEL_MASK | + OPCR_SPEED_MASK | + OPCR_OVERHEAD_ID_MASK); + opcr |= cpu_to_be32(1 << PCR_P2P_CONN_SHIFT); + opcr |= cpu_to_be32(xspd << OPCR_XSPEED_SHIFT); + opcr |= cpu_to_be32(c->resources.channel << PCR_CHANNEL_SHIFT); + opcr |= cpu_to_be32(spd << OPCR_SPEED_SHIFT); + opcr |= cpu_to_be32(get_overhead_id(c) << OPCR_OVERHEAD_ID_SHIFT); + + return opcr; +} + +static int pcr_set_check(struct cmp_connection *c, __be32 pcr) +{ + if (pcr & cpu_to_be32(PCR_BCAST_CONN | + PCR_P2P_CONN_MASK)) { + cmp_error(c, "plug is already in use\n"); + return -EBUSY; + } + if (!(pcr & cpu_to_be32(PCR_ONLINE))) { + cmp_error(c, "plug is not on-line\n"); + return -ECONNREFUSED; + } + + return 0; +} + +/** + * cmp_connection_establish - establish a connection to the target + * @c: the connection manager + * + * This function establishes a point-to-point connection from the local + * computer to the target by allocating isochronous resources (channel and + * bandwidth) and setting the target's input/output plug control register. + * When this function succeeds, the caller is responsible for starting + * transmitting packets. + */ +int cmp_connection_establish(struct cmp_connection *c) +{ + int err; + + guard(mutex)(&c->mutex); + + if (WARN_ON(c->connected)) + return -EISCONN; + +retry_after_bus_reset: + if (c->direction == CMP_OUTPUT) + err = pcr_modify(c, opcr_set_modify, pcr_set_check, + ABORT_ON_BUS_RESET); + else + err = pcr_modify(c, ipcr_set_modify, pcr_set_check, + ABORT_ON_BUS_RESET); + + if (err == -EAGAIN) { + err = fw_iso_resources_update(&c->resources); + if (err >= 0) + goto retry_after_bus_reset; + } + if (err >= 0) + c->connected = true; + + return err; +} +EXPORT_SYMBOL(cmp_connection_establish); + +static __be32 pcr_break_modify(struct cmp_connection *c, __be32 pcr) +{ + return pcr & ~cpu_to_be32(PCR_BCAST_CONN | PCR_P2P_CONN_MASK); +} + +/** + * cmp_connection_break - break the connection to the target + * @c: the connection manager + * + * This function deactives the connection in the target's input/output plug + * control register, and frees the isochronous resources of the connection. + * Before calling this function, the caller should cease transmitting packets. + */ +void cmp_connection_break(struct cmp_connection *c) +{ + int err; + + guard(mutex)(&c->mutex); + + if (!c->connected) + return; + + err = pcr_modify(c, pcr_break_modify, NULL, SUCCEED_ON_BUS_RESET); + if (err < 0) + cmp_error(c, "plug is still connected\n"); + + c->connected = false; +} +EXPORT_SYMBOL(cmp_connection_break); -- cgit v1.3.1