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/simpleboot.c | 87 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 arch/powerpc/boot/simpleboot.c (limited to 'arch/powerpc/boot/simpleboot.c') diff --git a/arch/powerpc/boot/simpleboot.c b/arch/powerpc/boot/simpleboot.c new file mode 100644 index 000000000..27591df41 --- /dev/null +++ b/arch/powerpc/boot/simpleboot.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * The simple platform -- for booting when firmware doesn't supply a device + * tree or any platform configuration information. + * All data is extracted from an embedded device tree + * blob. + * + * Authors: Scott Wood + * Grant Likely + * + * Copyright (c) 2007 Freescale Semiconductor, Inc. + * Copyright (c) 2008 Secret Lab Technologies Ltd. + */ + +#include "ops.h" +#include "types.h" +#include "io.h" +#include "stdio.h" +#include + +BSS_STACK(4*1024); + +extern int platform_specific_init(void) __attribute__((weak)); + +void platform_init(unsigned long r3, unsigned long r4, unsigned long r5, + unsigned long r6, unsigned long r7) +{ + const u32 *na, *ns, *reg, *timebase; + u64 memsize64; + int node, size, i; + + /* Make sure FDT blob is sane */ + if (fdt_check_header(_dtb_start) != 0) + fatal("Invalid device tree blob\n"); + + /* Find the #address-cells and #size-cells properties */ + node = fdt_path_offset(_dtb_start, "/"); + if (node < 0) + fatal("Cannot find root node\n"); + na = fdt_getprop(_dtb_start, node, "#address-cells", &size); + if (!na || (size != 4)) + fatal("Cannot find #address-cells property"); + ns = fdt_getprop(_dtb_start, node, "#size-cells", &size); + if (!ns || (size != 4)) + fatal("Cannot find #size-cells property"); + + /* Find the memory range */ + node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type", + "memory", sizeof("memory")); + if (node < 0) + fatal("Cannot find memory node\n"); + reg = fdt_getprop(_dtb_start, node, "reg", &size); + if (size < (*na+*ns) * sizeof(u32)) + fatal("cannot get memory range\n"); + + /* Only interested in memory based at 0 */ + for (i = 0; i < *na; i++) + if (*reg++ != 0) + fatal("Memory range is not based at address 0\n"); + + /* get the memsize and truncate it to under 4G on 32 bit machines */ + memsize64 = 0; + for (i = 0; i < *ns; i++) + memsize64 = (memsize64 << 32) | *reg++; + if (sizeof(void *) == 4 && memsize64 >= 0x100000000ULL) + memsize64 = 0xffffffff; + + /* finally, setup the timebase */ + node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type", + "cpu", sizeof("cpu")); + if (node < 0) + fatal("Cannot find cpu node\n"); + timebase = fdt_getprop(_dtb_start, node, "timebase-frequency", &size); + if (timebase && (size == 4)) + timebase_period_ns = 1000000000 / *timebase; + + /* Now we have the memory size; initialize the heap */ + simple_alloc_init(_end, memsize64 - (unsigned long)_end, 32, 64); + + /* prepare the device tree and find the console */ + fdt_init(_dtb_start); + + if (platform_specific_init) + platform_specific_init(); + + serial_console_init(); +} -- cgit v1.3.1