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/ugecon.c | 142 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 arch/powerpc/boot/ugecon.c (limited to 'arch/powerpc/boot/ugecon.c') diff --git a/arch/powerpc/boot/ugecon.c b/arch/powerpc/boot/ugecon.c new file mode 100644 index 000000000..938a38bd4 --- /dev/null +++ b/arch/powerpc/boot/ugecon.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * arch/powerpc/boot/ugecon.c + * + * USB Gecko bootwrapper console. + * Copyright (C) 2008-2009 The GameCube Linux Team + * Copyright (C) 2008,2009 Albert Herranz + */ + +#include +#include "stdio.h" +#include "types.h" +#include "io.h" +#include "ops.h" + + +#define EXI_CLK_32MHZ 5 + +#define EXI_CSR 0x00 +#define EXI_CSR_CLKMASK (0x7<<4) +#define EXI_CSR_CLK_32MHZ (EXI_CLK_32MHZ<<4) +#define EXI_CSR_CSMASK (0x7<<7) +#define EXI_CSR_CS_0 (0x1<<7) /* Chip Select 001 */ + +#define EXI_CR 0x0c +#define EXI_CR_TSTART (1<<0) +#define EXI_CR_WRITE (1<<2) +#define EXI_CR_READ_WRITE (2<<2) +#define EXI_CR_TLEN(len) (((len)-1)<<4) + +#define EXI_DATA 0x10 + + +/* virtual address base for input/output, retrieved from device tree */ +static void *ug_io_base; + + +static u32 ug_io_transaction(u32 in) +{ + u32 *csr_reg = ug_io_base + EXI_CSR; + u32 *data_reg = ug_io_base + EXI_DATA; + u32 *cr_reg = ug_io_base + EXI_CR; + u32 csr, data, cr; + + /* select */ + csr = EXI_CSR_CLK_32MHZ | EXI_CSR_CS_0; + out_be32(csr_reg, csr); + + /* read/write */ + data = in; + out_be32(data_reg, data); + cr = EXI_CR_TLEN(2) | EXI_CR_READ_WRITE | EXI_CR_TSTART; + out_be32(cr_reg, cr); + + while (in_be32(cr_reg) & EXI_CR_TSTART) + barrier(); + + /* deselect */ + out_be32(csr_reg, 0); + + data = in_be32(data_reg); + return data; +} + +static int ug_is_txfifo_ready(void) +{ + return ug_io_transaction(0xc0000000) & 0x04000000; +} + +static void ug_raw_putc(char ch) +{ + ug_io_transaction(0xb0000000 | (ch << 20)); +} + +static void ug_putc(char ch) +{ + int count = 16; + + if (!ug_io_base) + return; + + while (!ug_is_txfifo_ready() && count--) + barrier(); + if (count >= 0) + ug_raw_putc(ch); +} + +void ug_console_write(const char *buf, int len) +{ + char *b = (char *)buf; + + while (len--) { + if (*b == '\n') + ug_putc('\r'); + ug_putc(*b++); + } +} + +static int ug_is_adapter_present(void) +{ + if (!ug_io_base) + return 0; + return ug_io_transaction(0x90000000) == 0x04700000; +} + +static void *ug_grab_exi_io_base(void) +{ + u32 v; + void *devp; + + devp = find_node_by_compatible(NULL, "nintendo,flipper-exi"); + if (devp == NULL) + goto err_out; + if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v)) + goto err_out; + + return (void *)v; + +err_out: + return NULL; +} + +void *ug_probe(void) +{ + void *exi_io_base; + int i; + + exi_io_base = ug_grab_exi_io_base(); + if (!exi_io_base) + return NULL; + + /* look for a usbgecko on memcard slots A and B */ + for (i = 0; i < 2; i++) { + ug_io_base = exi_io_base + 0x14 * i; + if (ug_is_adapter_present()) + break; + } + if (i == 2) + ug_io_base = NULL; + return ug_io_base; +} + -- cgit v1.3.1