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 --- arch/powerpc/boot/devtree.c | 377 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 377 insertions(+) create mode 100644 arch/powerpc/boot/devtree.c (limited to 'arch/powerpc/boot/devtree.c') diff --git a/arch/powerpc/boot/devtree.c b/arch/powerpc/boot/devtree.c new file mode 100644 index 000000000..58fbcfcc9 --- /dev/null +++ b/arch/powerpc/boot/devtree.c @@ -0,0 +1,377 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * devtree.c - convenience functions for device tree manipulation + * Copyright 2007 David Gibson, IBM Corporation. + * Copyright (c) 2007 Freescale Semiconductor, Inc. + * + * Authors: David Gibson + * Scott Wood + */ +#include +#include +#include "types.h" +#include "string.h" +#include "stdio.h" +#include "ops.h" +#include "of.h" + +void dt_fixup_memory(u64 start, u64 size) +{ + void *root, *memory; + int naddr, nsize, i; + u32 memreg[4]; + + root = finddevice("/"); + if (getprop(root, "#address-cells", &naddr, sizeof(naddr)) < 0) + naddr = 2; + else + naddr = be32_to_cpu(naddr); + if (naddr < 1 || naddr > 2) + fatal("Can't cope with #address-cells == %d in /\n\r", naddr); + + if (getprop(root, "#size-cells", &nsize, sizeof(nsize)) < 0) + nsize = 1; + else + nsize = be32_to_cpu(nsize); + if (nsize < 1 || nsize > 2) + fatal("Can't cope with #size-cells == %d in /\n\r", nsize); + + i = 0; + if (naddr == 2) + memreg[i++] = cpu_to_be32(start >> 32); + memreg[i++] = cpu_to_be32(start & 0xffffffff); + if (nsize == 2) + memreg[i++] = cpu_to_be32(size >> 32); + memreg[i++] = cpu_to_be32(size & 0xffffffff); + + memory = finddevice("/memory"); + if (! memory) { + memory = create_node(NULL, "memory"); + setprop_str(memory, "device_type", "memory"); + } + + printf("Memory <- <0x%x", be32_to_cpu(memreg[0])); + for (i = 1; i < (naddr + nsize); i++) + printf(" 0x%x", be32_to_cpu(memreg[i])); + printf("> (%ldMB)\n\r", (unsigned long)(size >> 20)); + + setprop(memory, "reg", memreg, (naddr + nsize)*sizeof(u32)); +} + +#define MHZ(x) ((x + 500000) / 1000000) + +void dt_fixup_cpu_clocks(u32 cpu, u32 tb, u32 bus) +{ + void *devp = NULL; + + printf("CPU clock-frequency <- 0x%x (%dMHz)\n\r", cpu, MHZ(cpu)); + printf("CPU timebase-frequency <- 0x%x (%dMHz)\n\r", tb, MHZ(tb)); + if (bus > 0) + printf("CPU bus-frequency <- 0x%x (%dMHz)\n\r", bus, MHZ(bus)); + + while ((devp = find_node_by_devtype(devp, "cpu"))) { + setprop_val(devp, "clock-frequency", cpu_to_be32(cpu)); + setprop_val(devp, "timebase-frequency", cpu_to_be32(tb)); + if (bus > 0) + setprop_val(devp, "bus-frequency", cpu_to_be32(bus)); + } + + timebase_period_ns = 1000000000 / tb; +} + +void dt_fixup_clock(const char *path, u32 freq) +{ + void *devp = finddevice(path); + + if (devp) { + printf("%s: clock-frequency <- %x (%dMHz)\n\r", path, freq, MHZ(freq)); + setprop_val(devp, "clock-frequency", cpu_to_be32(freq)); + } +} + +void dt_fixup_mac_address_by_alias(const char *alias, const u8 *addr) +{ + void *devp = find_node_by_alias(alias); + + if (devp) { + printf("%s: local-mac-address <-" + " %02x:%02x:%02x:%02x:%02x:%02x\n\r", alias, + addr[0], addr[1], addr[2], + addr[3], addr[4], addr[5]); + + setprop(devp, "local-mac-address", addr, 6); + } +} + +void dt_fixup_mac_address(u32 index, const u8 *addr) +{ + void *devp = find_node_by_prop_value(NULL, "linux,network-index", + (void*)&index, sizeof(index)); + + if (devp) { + printf("ENET%d: local-mac-address <-" + " %02x:%02x:%02x:%02x:%02x:%02x\n\r", index, + addr[0], addr[1], addr[2], + addr[3], addr[4], addr[5]); + + setprop(devp, "local-mac-address", addr, 6); + } +} + +void __dt_fixup_mac_addresses(u32 startindex, ...) +{ + va_list ap; + u32 index = startindex; + const u8 *addr; + + va_start(ap, startindex); + + while ((addr = va_arg(ap, const u8 *))) + dt_fixup_mac_address(index++, addr); + + va_end(ap); +} + +#define MAX_ADDR_CELLS 4 + +void dt_get_reg_format(void *node, u32 *naddr, u32 *nsize) +{ + if (getprop(node, "#address-cells", naddr, 4) != 4) + *naddr = 2; + else + *naddr = be32_to_cpu(*naddr); + if (getprop(node, "#size-cells", nsize, 4) != 4) + *nsize = 1; + else + *nsize = be32_to_cpu(*nsize); +} + +static void copy_val(u32 *dest, u32 *src, int naddr) +{ + int pad = MAX_ADDR_CELLS - naddr; + + memset(dest, 0, pad * 4); + memcpy(dest + pad, src, naddr * 4); +} + +static int sub_reg(u32 *reg, u32 *sub) +{ + int i, borrow = 0; + + for (i = MAX_ADDR_CELLS - 1; i >= 0; i--) { + int prev_borrow = borrow; + borrow = reg[i] < sub[i] + prev_borrow; + reg[i] -= sub[i] + prev_borrow; + } + + return !borrow; +} + +static int add_reg(u32 *reg, u32 *add, int naddr) +{ + int i, carry = 0; + + for (i = MAX_ADDR_CELLS - 1; i >= MAX_ADDR_CELLS - naddr; i--) { + u64 tmp = (u64)be32_to_cpu(reg[i]) + be32_to_cpu(add[i]) + carry; + carry = tmp >> 32; + reg[i] = cpu_to_be32((u32)tmp); + } + + return !carry; +} + +/* It is assumed that if the first byte of reg fits in a + * range, then the whole reg block fits. + */ +static int compare_reg(u32 *reg, u32 *range, u32 *rangesize) +{ + int i; + u32 end; + + for (i = 0; i < MAX_ADDR_CELLS; i++) { + if (be32_to_cpu(reg[i]) < be32_to_cpu(range[i])) + return 0; + if (be32_to_cpu(reg[i]) > be32_to_cpu(range[i])) + break; + } + + for (i = 0; i < MAX_ADDR_CELLS; i++) { + end = be32_to_cpu(range[i]) + be32_to_cpu(rangesize[i]); + + if (be32_to_cpu(reg[i]) < end) + break; + if (be32_to_cpu(reg[i]) > end) + return 0; + } + + return reg[i] != end; +} + +/* reg must be MAX_ADDR_CELLS */ +static int find_range(u32 *reg, u32 *ranges, int nregaddr, + int naddr, int nsize, int buflen) +{ + int nrange = nregaddr + naddr + nsize; + int i; + + for (i = 0; i + nrange <= buflen; i += nrange) { + u32 range_addr[MAX_ADDR_CELLS]; + u32 range_size[MAX_ADDR_CELLS]; + + copy_val(range_addr, ranges + i, nregaddr); + copy_val(range_size, ranges + i + nregaddr + naddr, nsize); + + if (compare_reg(reg, range_addr, range_size)) + return i; + } + + return -1; +} + +/* Currently only generic buses without special encodings are supported. + * In particular, PCI is not supported. Also, only the beginning of the + * reg block is tracked; size is ignored except in ranges. + */ +static u32 prop_buf[MAX_PROP_LEN / 4]; + +static int dt_xlate(void *node, int res, int reglen, unsigned long *addr, + unsigned long *size) +{ + u32 last_addr[MAX_ADDR_CELLS]; + u32 this_addr[MAX_ADDR_CELLS]; + void *parent; + u64 ret_addr, ret_size; + u32 naddr, nsize, prev_naddr, prev_nsize; + int buflen, offset; + + parent = get_parent(node); + if (!parent) + return 0; + + dt_get_reg_format(parent, &naddr, &nsize); + if (nsize > 2) + return 0; + + offset = (naddr + nsize) * res; + + if (reglen < offset + naddr + nsize || + MAX_PROP_LEN < (offset + naddr + nsize) * 4) + return 0; + + copy_val(last_addr, prop_buf + offset, naddr); + + ret_size = be32_to_cpu(prop_buf[offset + naddr]); + if (nsize == 2) { + ret_size <<= 32; + ret_size |= be32_to_cpu(prop_buf[offset + naddr + 1]); + } + + for (;;) { + prev_naddr = naddr; + prev_nsize = nsize; + node = parent; + + parent = get_parent(node); + if (!parent) + break; + + dt_get_reg_format(parent, &naddr, &nsize); + + buflen = getprop(node, "ranges", prop_buf, + sizeof(prop_buf)); + if (buflen == 0) + continue; + if (buflen < 0 || buflen > sizeof(prop_buf)) + return 0; + + offset = find_range(last_addr, prop_buf, prev_naddr, + naddr, prev_nsize, buflen / 4); + if (offset < 0) + return 0; + + copy_val(this_addr, prop_buf + offset, prev_naddr); + + if (!sub_reg(last_addr, this_addr)) + return 0; + + copy_val(this_addr, prop_buf + offset + prev_naddr, naddr); + + if (!add_reg(last_addr, this_addr, naddr)) + return 0; + } + + if (naddr > 2) + return 0; + + ret_addr = ((u64)be32_to_cpu(last_addr[2]) << 32) | be32_to_cpu(last_addr[3]); + if (sizeof(void *) == 4 && + (ret_addr >= 0x100000000ULL || ret_size > 0x100000000ULL || + ret_addr + ret_size > 0x100000000ULL)) + return 0; + + *addr = ret_addr; + if (size) + *size = ret_size; + + return 1; +} + +int dt_xlate_reg(void *node, int res, unsigned long *addr, unsigned long *size) +{ + int reglen; + + reglen = getprop(node, "reg", prop_buf, sizeof(prop_buf)) / 4; + return dt_xlate(node, res, reglen, addr, size); +} + +int dt_xlate_addr(void *node, u32 *buf, int buflen, unsigned long *xlated_addr) +{ + + if (buflen > sizeof(prop_buf)) + return 0; + + memcpy(prop_buf, buf, buflen); + return dt_xlate(node, 0, buflen / 4, xlated_addr, NULL); +} + +int dt_is_compatible(void *node, const char *compat) +{ + char *buf = (char *)prop_buf; + int len, pos; + + len = getprop(node, "compatible", buf, MAX_PROP_LEN); + if (len < 0) + return 0; + + for (pos = 0; pos < len; pos++) { + if (!strcmp(buf + pos, compat)) + return 1; + + pos += strnlen(&buf[pos], len - pos); + } + + return 0; +} + +int dt_get_virtual_reg(void *node, void **addr, int nres) +{ + unsigned long xaddr; + int n, i; + + n = getprop(node, "virtual-reg", addr, nres * 4); + if (n > 0) { + for (i = 0; i < n/4; i ++) + ((u32 *)addr)[i] = be32_to_cpu(((u32 *)addr)[i]); + return n / 4; + } + + for (n = 0; n < nres; n++) { + if (!dt_xlate_reg(node, n, &xaddr, NULL)) + break; + + addr[n] = (void *)xaddr; + } + + return n; +} + -- cgit v1.3.1