diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kvm-x86-fix-icebp-instruction-handling.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kvm-x86-fix-icebp-instruction-handling.patch | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kvm-x86-fix-icebp-instruction-handling.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kvm-x86-fix-icebp-instruction-handling.patch deleted file mode 100644 index aef1109b..00000000 --- a/common/recipes-kernel/linux/linux-yocto-4.9.21/0010-kvm-x86-fix-icebp-instruction-handling.patch +++ /dev/null @@ -1,88 +0,0 @@ -From 694ba89c4cb4e43ae4cb418ea46b1415f6d31ce7 Mon Sep 17 00:00:00 2001 -From: Linus Torvalds <torvalds@linux-foundation.org> -Date: Tue, 20 Mar 2018 12:16:59 -0700 -Subject: [PATCH 10/93] kvm/x86: fix icebp instruction handling - -commit 32d43cd391bacb5f0814c2624399a5dad3501d09 upstream. - -The undocumented 'icebp' instruction (aka 'int1') works pretty much like -'int3' in the absense of in-circuit probing equipment (except, -obviously, that it raises #DB instead of raising #BP), and is used by -some validation test-suites as such. - -But Andy Lutomirski noticed that his test suite acted differently in kvm -than on bare hardware. - -The reason is that kvm used an inexact test for the icebp instruction: -it just assumed that an all-zero VM exit qualification value meant that -the VM exit was due to icebp. - -That is not unlike the guess that do_debug() does for the actual -exception handling case, but it's purely a heuristic, not an absolute -rule. do_debug() does it because it wants to ascribe _some_ reasons to -the #DB that happened, and an empty %dr6 value means that 'icebp' is the -most likely casue and we have no better information. - -But kvm can just do it right, because unlike the do_debug() case, kvm -actually sees the real reason for the #DB in the VM-exit interruption -information field. - -So instead of relying on an inexact heuristic, just use the actual VM -exit information that says "it was 'icebp'". - -Right now the 'icebp' instruction isn't technically documented by Intel, -but that will hopefully change. The special "privileged software -exception" information _is_ actually mentioned in the Intel SDM, even -though the cause of it isn't enumerated. - -Reported-by: Andy Lutomirski <luto@kernel.org> -Tested-by: Paolo Bonzini <pbonzini@redhat.com> -Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> -Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> ---- - arch/x86/include/asm/vmx.h | 1 + - arch/x86/kvm/vmx.c | 9 ++++++++- - 2 files changed, 9 insertions(+), 1 deletion(-) - -diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h -index 6899cf1..9cbfbef 100644 ---- a/arch/x86/include/asm/vmx.h -+++ b/arch/x86/include/asm/vmx.h -@@ -309,6 +309,7 @@ enum vmcs_field { - #define INTR_TYPE_NMI_INTR (2 << 8) /* NMI */ - #define INTR_TYPE_HARD_EXCEPTION (3 << 8) /* processor exception */ - #define INTR_TYPE_SOFT_INTR (4 << 8) /* software interrupt */ -+#define INTR_TYPE_PRIV_SW_EXCEPTION (5 << 8) /* ICE breakpoint - undocumented */ - #define INTR_TYPE_SOFT_EXCEPTION (6 << 8) /* software exception */ - - /* GUEST_INTERRUPTIBILITY_INFO flags. */ -diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c -index 3c3558b..27f505d 100644 ---- a/arch/x86/kvm/vmx.c -+++ b/arch/x86/kvm/vmx.c -@@ -1053,6 +1053,13 @@ static inline bool is_machine_check(u32 intr_info) - (INTR_TYPE_HARD_EXCEPTION | MC_VECTOR | INTR_INFO_VALID_MASK); - } - -+/* Undocumented: icebp/int1 */ -+static inline bool is_icebp(u32 intr_info) -+{ -+ return (intr_info & (INTR_INFO_INTR_TYPE_MASK | INTR_INFO_VALID_MASK)) -+ == (INTR_TYPE_PRIV_SW_EXCEPTION | INTR_INFO_VALID_MASK); -+} -+ - static inline bool cpu_has_vmx_msr_bitmap(void) - { - return vmcs_config.cpu_based_exec_ctrl & CPU_BASED_USE_MSR_BITMAPS; -@@ -5708,7 +5715,7 @@ static int handle_exception(struct kvm_vcpu *vcpu) - (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))) { - vcpu->arch.dr6 &= ~15; - vcpu->arch.dr6 |= dr6 | DR6_RTM; -- if (!(dr6 & ~DR6_RESERVED)) /* icebp */ -+ if (is_icebp(intr_info)) - skip_emulated_instruction(vcpu); - - kvm_queue_exception(vcpu, DB_VECTOR); --- -2.7.4 - |