diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0006-KVM-X86-Fix-operand-address-size-during-instruction-.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0006-KVM-X86-Fix-operand-address-size-during-instruction-.patch | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0006-KVM-X86-Fix-operand-address-size-during-instruction-.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0006-KVM-X86-Fix-operand-address-size-during-instruction-.patch new file mode 100644 index 00000000..9430b597 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0006-KVM-X86-Fix-operand-address-size-during-instruction-.patch @@ -0,0 +1,67 @@ +From 399e9dee4411858aa4eb8894f031ff68ab3b5e9f Mon Sep 17 00:00:00 2001 +From: Wanpeng Li <wanpeng.li@hotmail.com> +Date: Sun, 5 Nov 2017 16:54:47 -0800 +Subject: [PATCH 06/33] KVM: X86: Fix operand/address-size during instruction + decoding +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +[ Upstream commit 3853be2603191829b442b64dac6ae8ba0c027bf9 ] + +Pedro reported: + During tests that we conducted on KVM, we noticed that executing a "PUSH %ES" + instruction under KVM produces different results on both memory and the SP + register depending on whether EPT support is enabled. With EPT the SP is + reduced by 4 bytes (and the written value is 0-padded) but without EPT support + it is only reduced by 2 bytes. The difference can be observed when the CS.DB + field is 1 (32-bit) but not when it's 0 (16-bit). + +The internal segment descriptor cache exist even in real/vm8096 mode. The CS.D +also should be respected instead of just default operand/address-size/66H +prefix/67H prefix during instruction decoding. This patch fixes it by also +adjusting operand/address-size according to CS.D. + +Reported-by: Pedro Fonseca <pfonseca@cs.washington.edu> +Tested-by: Pedro Fonseca <pfonseca@cs.washington.edu> +Cc: Paolo Bonzini <pbonzini@redhat.com> +Cc: Radim Krčmář <rkrcmar@redhat.com> +Cc: Nadav Amit <nadav.amit@gmail.com> +Cc: Pedro Fonseca <pfonseca@cs.washington.edu> +Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> +Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> +Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> +Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/kvm/emulate.c | 7 +++++++ + 1 file changed, 7 insertions(+) + +diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c +index 9f676ad..9984daf 100644 +--- a/arch/x86/kvm/emulate.c ++++ b/arch/x86/kvm/emulate.c +@@ -4971,6 +4971,8 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) + bool op_prefix = false; + bool has_seg_override = false; + struct opcode opcode; ++ u16 dummy; ++ struct desc_struct desc; + + ctxt->memop.type = OP_NONE; + ctxt->memopp = NULL; +@@ -4989,6 +4991,11 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) + switch (mode) { + case X86EMUL_MODE_REAL: + case X86EMUL_MODE_VM86: ++ def_op_bytes = def_ad_bytes = 2; ++ ctxt->ops->get_segment(ctxt, &dummy, &desc, NULL, VCPU_SREG_CS); ++ if (desc.d) ++ def_op_bytes = def_ad_bytes = 4; ++ break; + case X86EMUL_MODE_PROT16: + def_op_bytes = def_ad_bytes = 2; + break; +-- +2.7.4 + |