KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

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 <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 383 insertions, 0 deletions

diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
new file mode 100644
index 000000000..ca068df1f
--- /dev/null
+++ b/lib/crypto/Makefile
@@ -0,0 +1,383 @@
+# SPDX-License-Identifier: GPL-2.0
+
+aflags-thumb2-$(CONFIG_THUMB2_KERNEL)  := -U__thumb2__ -D__thumb2__=1
+
+quiet_cmd_perlasm = PERLASM $@
+      cmd_perlasm = $(PERL) $(<) > $(@)
+
+quiet_cmd_perlasm_with_args = PERLASM $@
+      cmd_perlasm_with_args = $(PERL) $(<) void $(@)
+
+ppc64-perlasm-flavour-y := linux-ppc64
+ppc64-perlasm-flavour-$(CONFIG_PPC64_ELF_ABI_V2) := linux-ppc64-elfv2
+ppc64-perlasm-flavour-$(CONFIG_CPU_LITTLE_ENDIAN) := linux-ppc64le
+
+obj-$(CONFIG_KUNIT)				+= tests/
+
+obj-$(CONFIG_CRYPTO_HASH_INFO)			+= hash_info.o
+
+obj-$(CONFIG_CRYPTO_LIB_UTILS)			+= libcryptoutils.o
+libcryptoutils-y				:= memneq.o utils.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_AES) += libaes.o
+libaes-y := aes.o
+ifeq ($(CONFIG_CRYPTO_LIB_AES_ARCH),y)
+CFLAGS_aes.o += -I$(src)/$(SRCARCH)
+
+libaes-$(CONFIG_ARM) += arm/aes-cipher-core.o
+libaes-$(CONFIG_ARM64) += arm64/aes-cipher-core.o \
+			  arm64/aes-ce-core.o \
+			  arm64/aes-ce.o \
+			  arm64/aes-neon.o
+
+ifeq ($(CONFIG_PPC),y)
+ifeq ($(CONFIG_SPE),y)
+libaes-y += powerpc/aes-spe-core.o \
+	    powerpc/aes-spe-keys.o \
+	    powerpc/aes-spe-modes.o \
+	    powerpc/aes-tab-4k.o
+else
+libaes-y += powerpc/aesp8-ppc.o
+quiet_cmd_perlasm_aes = PERLASM $@
+      cmd_perlasm_aes = $(PERL) $< $(ppc64-perlasm-flavour-y) $@
+# Use if_changed instead of cmd, in case the flavour changed.
+$(obj)/powerpc/aesp8-ppc.S: $(src)/powerpc/aesp8-ppc.pl FORCE
+	$(call if_changed,perlasm_aes)
+targets += powerpc/aesp8-ppc.S
+OBJECT_FILES_NON_STANDARD_powerpc/aesp8-ppc.o := y
+endif # !CONFIG_SPE
+endif # CONFIG_PPC
+
+libaes-$(CONFIG_RISCV) += riscv/aes-riscv64-zvkned.o
+libaes-$(CONFIG_SPARC) += sparc/aes_asm.o
+libaes-$(CONFIG_X86) += x86/aes-aesni.o
+endif # CONFIG_CRYPTO_LIB_AES_ARCH
+
+# clean-files must be defined unconditionally
+clean-files += powerpc/aesp8-ppc.S
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_AESCFB)			+= libaescfb.o
+libaescfb-y					:= aescfb.o
+
+obj-$(CONFIG_CRYPTO_LIB_ARC4)			+= libarc4.o
+libarc4-y					:= arc4.o
+
+obj-$(CONFIG_CRYPTO_LIB_GF128MUL)		+= gf128mul.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_BLAKE2B) += libblake2b.o
+libblake2b-y := blake2b.o
+ifeq ($(CONFIG_CRYPTO_LIB_BLAKE2B_ARCH),y)
+CFLAGS_blake2b.o += -I$(src)/$(SRCARCH)
+libblake2b-$(CONFIG_ARM) += arm/blake2b-neon-core.o
+endif # CONFIG_CRYPTO_LIB_BLAKE2B_ARCH
+
+################################################################################
+
+# blake2s is used by the /dev/random driver which is always builtin
+obj-y += blake2s.o
+ifeq ($(CONFIG_CRYPTO_LIB_BLAKE2S_ARCH),y)
+CFLAGS_blake2s.o += -I$(src)/$(SRCARCH)
+obj-$(CONFIG_ARM) += arm/blake2s-core.o
+obj-$(CONFIG_X86) += x86/blake2s-core.o
+endif
+
+################################################################################
+
+# chacha20_block() is used by the /dev/random driver which is always builtin
+obj-y += chacha-block-generic.o
+
+obj-$(CONFIG_CRYPTO_LIB_CHACHA) += libchacha.o
+libchacha-y := chacha.o
+
+ifeq ($(CONFIG_CRYPTO_LIB_CHACHA_ARCH),y)
+CFLAGS_chacha.o += -I$(src)/$(SRCARCH)
+
+ifeq ($(CONFIG_ARM),y)
+libchacha-y += arm/chacha-scalar-core.o
+libchacha-$(CONFIG_KERNEL_MODE_NEON) += arm/chacha-neon-core.o
+endif
+
+libchacha-$(CONFIG_ARM64) += arm64/chacha-neon-core.o
+
+ifeq ($(CONFIG_MIPS),y)
+libchacha-y += mips/chacha-core.o
+AFLAGS_mips/chacha-core.o += -O2 # needed to fill branch delay slots
+endif
+
+libchacha-$(CONFIG_PPC) += powerpc/chacha-p10le-8x.o
+libchacha-$(CONFIG_RISCV) += riscv/chacha-riscv64-zvkb.o
+libchacha-$(CONFIG_S390) += s390/chacha-s390.o
+libchacha-$(CONFIG_X86) += x86/chacha-ssse3-x86_64.o \
+			   x86/chacha-avx2-x86_64.o \
+			   x86/chacha-avx512vl-x86_64.o
+endif # CONFIG_CRYPTO_LIB_CHACHA_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_CHACHA20POLY1305)	+= libchacha20poly1305.o
+libchacha20poly1305-y				+= chacha20poly1305.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_CURVE25519) += libcurve25519.o
+libcurve25519-y := curve25519.o
+
+# Disable GCOV in odd or sensitive code
+GCOV_PROFILE_curve25519.o := n
+
+ifeq ($(CONFIG_ARCH_SUPPORTS_INT128),y)
+libcurve25519-$(CONFIG_CRYPTO_LIB_CURVE25519_GENERIC) += curve25519-hacl64.o
+else
+libcurve25519-$(CONFIG_CRYPTO_LIB_CURVE25519_GENERIC) += curve25519-fiat32.o
+endif
+# clang versions prior to 18 may blow out the stack with KASAN
+ifeq ($(CONFIG_CC_IS_CLANG)_$(call clang-min-version, 180000),y_)
+KASAN_SANITIZE_curve25519-hacl64.o := n
+endif
+
+ifeq ($(CONFIG_CRYPTO_LIB_CURVE25519_ARCH),y)
+CFLAGS_curve25519.o += -I$(src)/$(SRCARCH)
+libcurve25519-$(CONFIG_ARM) += arm/curve25519-core.o
+libcurve25519-$(CONFIG_PPC) += powerpc/curve25519-ppc64le_asm.o
+endif
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_DES)			+= libdes.o
+libdes-y					:= des.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_GF128HASH) += libgf128hash.o
+libgf128hash-y := gf128hash.o
+ifeq ($(CONFIG_CRYPTO_LIB_GF128HASH_ARCH),y)
+CFLAGS_gf128hash.o += -I$(src)/$(SRCARCH)
+libgf128hash-$(CONFIG_ARM) += arm/ghash-neon-core.o
+libgf128hash-$(CONFIG_ARM64) += arm64/ghash-neon-core.o \
+				arm64/polyval-ce-core.o
+
+ifeq ($(CONFIG_PPC),y)
+libgf128hash-y += powerpc/ghashp8-ppc.o
+quiet_cmd_perlasm_ghash = PERLASM $@
+      cmd_perlasm_ghash = $(PERL) $< $(ppc64-perlasm-flavour-y) $@
+$(obj)/powerpc/ghashp8-ppc.S: $(src)/powerpc/ghashp8-ppc.pl FORCE
+	$(call if_changed,perlasm_ghash)
+targets += powerpc/ghashp8-ppc.S
+OBJECT_FILES_NON_STANDARD_powerpc/ghashp8-ppc.o := y
+endif
+
+libgf128hash-$(CONFIG_RISCV) += riscv/ghash-riscv64-zvkg.o
+libgf128hash-$(CONFIG_X86) += x86/ghash-pclmul.o \
+			      x86/polyval-pclmul-avx.o
+endif # CONFIG_CRYPTO_LIB_GF128HASH_ARCH
+
+# clean-files must be defined unconditionally
+clean-files += powerpc/ghashp8-ppc.S
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_MD5) += libmd5.o
+libmd5-y := md5.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_MLDSA) += libmldsa.o
+libmldsa-y := mldsa.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_NH) += libnh.o
+libnh-y := nh.o
+ifeq ($(CONFIG_CRYPTO_LIB_NH_ARCH),y)
+CFLAGS_nh.o += -I$(src)/$(SRCARCH)
+libnh-$(CONFIG_ARM) += arm/nh-neon-core.o
+libnh-$(CONFIG_ARM64) += arm64/nh-neon-core.o
+libnh-$(CONFIG_X86) += x86/nh-sse2.o x86/nh-avx2.o
+endif
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_POLY1305) += libpoly1305.o
+libpoly1305-y := poly1305.o
+ifeq ($(CONFIG_ARCH_SUPPORTS_INT128),y)
+libpoly1305-$(CONFIG_CRYPTO_LIB_POLY1305_GENERIC) += poly1305-donna64.o
+else
+libpoly1305-$(CONFIG_CRYPTO_LIB_POLY1305_GENERIC) += poly1305-donna32.o
+endif
+
+ifeq ($(CONFIG_CRYPTO_LIB_POLY1305_ARCH),y)
+CFLAGS_poly1305.o += -I$(src)/$(SRCARCH)
+
+ifeq ($(CONFIG_ARM),y)
+libpoly1305-y += arm/poly1305-core.o
+$(obj)/arm/poly1305-core.S: $(src)/arm/poly1305-armv4.pl
+	$(call cmd,perlasm)
+# massage the perlasm code a bit so we only get the NEON routine if we need it
+poly1305-aflags-$(CONFIG_CPU_V7) := -U__LINUX_ARM_ARCH__ -D__LINUX_ARM_ARCH__=5
+poly1305-aflags-$(CONFIG_KERNEL_MODE_NEON) := -U__LINUX_ARM_ARCH__ -D__LINUX_ARM_ARCH__=7
+AFLAGS_arm/poly1305-core.o += $(poly1305-aflags-y) $(aflags-thumb2-y)
+endif
+
+ifeq ($(CONFIG_ARM64),y)
+libpoly1305-y += arm64/poly1305-core.o
+$(obj)/arm64/poly1305-core.S: $(src)/arm64/poly1305-armv8.pl
+	$(call cmd,perlasm_with_args)
+endif
+
+ifeq ($(CONFIG_MIPS),y)
+libpoly1305-y += mips/poly1305-core.o
+poly1305-perlasm-flavour-$(CONFIG_32BIT) := o32
+poly1305-perlasm-flavour-$(CONFIG_64BIT) := 64
+quiet_cmd_perlasm_poly1305 = PERLASM $@
+      cmd_perlasm_poly1305 = $(PERL) $< $(poly1305-perlasm-flavour-y) $@
+# Use if_changed instead of cmd, in case the flavour changed.
+$(obj)/mips/poly1305-core.S: $(src)/mips/poly1305-mips.pl FORCE
+	$(call if_changed,perlasm_poly1305)
+targets += mips/poly1305-core.S
+endif
+
+libpoly1305-$(CONFIG_PPC) += powerpc/poly1305-p10le_64.o
+
+ifeq ($(CONFIG_RISCV),y)
+libpoly1305-y += riscv/poly1305-core.o
+poly1305-perlasm-flavour-$(CONFIG_32BIT) := 32
+poly1305-perlasm-flavour-$(CONFIG_64BIT) := 64
+quiet_cmd_perlasm_poly1305 = PERLASM $@
+      cmd_perlasm_poly1305 = $(PERL) $< $(poly1305-perlasm-flavour-y) $@
+# Use if_changed instead of cmd, in case the flavour changed.
+$(obj)/riscv/poly1305-core.S: $(src)/riscv/poly1305-riscv.pl FORCE
+	$(call if_changed,perlasm_poly1305)
+targets += riscv/poly1305-core.S
+AFLAGS_riscv/poly1305-core.o += -Dpoly1305_init=poly1305_block_init
+endif
+
+ifeq ($(CONFIG_X86),y)
+libpoly1305-y += x86/poly1305-x86_64-cryptogams.o
+$(obj)/x86/poly1305-x86_64-cryptogams.S: $(src)/x86/poly1305-x86_64-cryptogams.pl
+	$(call cmd,perlasm)
+endif
+
+endif # CONFIG_CRYPTO_LIB_POLY1305_ARCH
+
+# clean-files must be defined unconditionally
+clean-files += arm/poly1305-core.S \
+	       arm64/poly1305-core.S \
+	       mips/poly1305-core.S \
+	       riscv/poly1305-core.S \
+	       x86/poly1305-x86_64-cryptogams.S
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SHA1) += libsha1.o
+libsha1-y := sha1.o
+ifeq ($(CONFIG_CRYPTO_LIB_SHA1_ARCH),y)
+CFLAGS_sha1.o += -I$(src)/$(SRCARCH)
+ifeq ($(CONFIG_ARM),y)
+libsha1-y += arm/sha1-armv4-large.o
+libsha1-$(CONFIG_KERNEL_MODE_NEON) += arm/sha1-armv7-neon.o \
+				      arm/sha1-ce-core.o
+endif
+libsha1-$(CONFIG_ARM64) += arm64/sha1-ce-core.o
+ifeq ($(CONFIG_PPC),y)
+libsha1-y += powerpc/sha1-powerpc-asm.o
+libsha1-$(CONFIG_SPE) += powerpc/sha1-spe-asm.o
+endif
+libsha1-$(CONFIG_SPARC) += sparc/sha1_asm.o
+libsha1-$(CONFIG_X86) += x86/sha1-ssse3-and-avx.o \
+			 x86/sha1-avx2-asm.o \
+			 x86/sha1-ni-asm.o
+endif # CONFIG_CRYPTO_LIB_SHA1_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SHA256) += libsha256.o
+libsha256-y := sha256.o
+ifeq ($(CONFIG_CRYPTO_LIB_SHA256_ARCH),y)
+CFLAGS_sha256.o += -I$(src)/$(SRCARCH)
+
+ifeq ($(CONFIG_ARM),y)
+libsha256-y += arm/sha256-ce.o arm/sha256-core.o
+$(obj)/arm/sha256-core.S: $(src)/arm/sha256-armv4.pl
+	$(call cmd,perlasm)
+AFLAGS_arm/sha256-core.o += $(aflags-thumb2-y)
+endif
+
+ifeq ($(CONFIG_ARM64),y)
+libsha256-y += arm64/sha256-ce.o arm64/sha256-core.o
+$(obj)/arm64/sha256-core.S: $(src)/arm64/sha2-armv8.pl
+	$(call cmd,perlasm_with_args)
+endif
+
+libsha256-$(CONFIG_PPC) += powerpc/sha256-spe-asm.o
+libsha256-$(CONFIG_RISCV) += riscv/sha256-riscv64-zvknha_or_zvknhb-zvkb.o
+libsha256-$(CONFIG_SPARC) += sparc/sha256_asm.o
+libsha256-$(CONFIG_X86) += x86/sha256-ssse3-asm.o \
+			   x86/sha256-avx-asm.o \
+			   x86/sha256-avx2-asm.o \
+			   x86/sha256-ni-asm.o
+endif # CONFIG_CRYPTO_LIB_SHA256_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SHA512) += libsha512.o
+libsha512-y := sha512.o
+ifeq ($(CONFIG_CRYPTO_LIB_SHA512_ARCH),y)
+CFLAGS_sha512.o += -I$(src)/$(SRCARCH)
+
+ifeq ($(CONFIG_ARM),y)
+libsha512-y += arm/sha512-core.o
+$(obj)/arm/sha512-core.S: $(src)/arm/sha512-armv4.pl
+	$(call cmd,perlasm)
+AFLAGS_arm/sha512-core.o += $(aflags-thumb2-y)
+endif
+
+ifeq ($(CONFIG_ARM64),y)
+libsha512-y += arm64/sha512-ce-core.o arm64/sha512-core.o
+$(obj)/arm64/sha512-core.S: $(src)/arm64/sha2-armv8.pl
+	$(call cmd,perlasm_with_args)
+endif
+
+libsha512-$(CONFIG_RISCV) += riscv/sha512-riscv64-zvknhb-zvkb.o
+libsha512-$(CONFIG_SPARC) += sparc/sha512_asm.o
+libsha512-$(CONFIG_X86) += x86/sha512-ssse3-asm.o \
+			   x86/sha512-avx-asm.o \
+			   x86/sha512-avx2-asm.o
+endif # CONFIG_CRYPTO_LIB_SHA512_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SHA3) += libsha3.o
+libsha3-y := sha3.o
+
+ifeq ($(CONFIG_CRYPTO_LIB_SHA3_ARCH),y)
+CFLAGS_sha3.o += -I$(src)/$(SRCARCH)
+libsha3-$(CONFIG_ARM64) += arm64/sha3-ce-core.o
+endif # CONFIG_CRYPTO_LIB_SHA3_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SM3) += libsm3.o
+libsm3-y := sm3.o
+ifeq ($(CONFIG_CRYPTO_LIB_SM3_ARCH),y)
+CFLAGS_sm3.o += -I$(src)/$(SRCARCH)
+libsm3-$(CONFIG_ARM64) += arm64/sm3-ce-core.o \
+			  arm64/sm3-neon-core.o
+libsm3-$(CONFIG_RISCV) += riscv/sm3-riscv64-zvksh-zvkb.o
+libsm3-$(CONFIG_X86) += x86/sm3-avx-asm_64.o
+endif # CONFIG_CRYPTO_LIB_SM3_ARCH
+
+################################################################################
+
+obj-$(CONFIG_MPILIB) += mpi/
+
+obj-$(CONFIG_CRYPTO_SELFTESTS_FULL)		+= simd.o
+
+# clean-files must be defined unconditionally
+clean-files += arm/sha256-core.S arm/sha512-core.S
+clean-files += arm64/sha256-core.S arm64/sha512-core.S