linux-kernel - Re: [PATCH] kvm: x86: fix x86 eflags fixed bit

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <5C70C9AD-41C8-4ABE-A21B-BE6AACB356F9@gmail.com>
Date:	Wed, 8 Apr 2015 11:21:27 +0300
From:	Nadav Amit <nadav.amit@...il.com>
To:	Wanpeng Li <wanpeng.li@...ux.intel.com>
Cc:	kvm list <kvm@...r.kernel.org>, linux-kernel@...r.kernel.org,
	Paolo Bonzini <pbonzini@...hat.com>
Subject: Re: [PATCH] kvm: x86: fix x86 eflags fixed bit

Sorry for that - fixes 0efb04406de834d820f7ba150a00d1d3194aa8a6 ("KVM: x86:
removing redundant eflags bits definitions”).

Nadav

Wanpeng Li <wanpeng.li@...ux.intel.com> wrote:

> Guest can't be booted w/ ept=0, there is a message dumped as below:
> 
> If you're running a guest on an Intel machine without unrestricted mode
> support, the failure can be most likely due to the guest entering an invalid
> state for Intel VT. For example, the guest maybe running in big real mode
> which is not supported on less recent Intel processors.
> 
> EAX=00000011 EBX=f000d2f6 ECX=00006cac EDX=000f8956
> ESI=bffbdf62 EDI=00000000 EBP=00006c68 ESP=00006c68
> EIP=0000d187 EFL=00000004 [-----P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
> ES =e000 000e0000 ffffffff 00809300 DPL=0 DS16 [-WA]
> CS =f000 000f0000 ffffffff 00809b00 DPL=0 CS16 [-RA]
> SS =0000 00000000 ffffffff 00809300 DPL=0 DS16 [-WA]
> DS =0000 00000000 ffffffff 00809300 DPL=0 DS16 [-WA]
> FS =0000 00000000 ffffffff 00809300 DPL=0 DS16 [-WA]
> GS =0000 00000000 ffffffff 00809300 DPL=0 DS16 [-WA]
> LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT
> TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy
> GDT=     000f6a80 00000037
> IDT=     000f6abe 00000000
> CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000
> DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 
> DR6=00000000ffff0ff0 DR7=0000000000000400
> EFER=0000000000000000
> Code=01 1e b8 6a 2e 0f 01 16 74 6a 0f 20 c0 66 83 c8 01 0f 22 c0 <66> ea 8f d1 0f 00 08 00 b8 10 00 00 00 8e d8 8e c0 8e d0 8e e0 8e e8 89 c8 ff e2 89 c1 b8X
> 
> X86 eflags bit 1 is fixed set, which means that 1 << 1 is set instead of 1, 
> this patch fix it.
> 
> Signed-off-by: Wanpeng Li <wanpeng.li@...ux.intel.com>
> ---
> arch/x86/kvm/emulate.c |    6 +++---
> 1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
> index b304728..630bcb0 100644
> --- a/arch/x86/kvm/emulate.c
> +++ b/arch/x86/kvm/emulate.c
> @@ -2033,7 +2033,7 @@ static int emulate_iret_real(struct x86_emulate_ctxt *ctxt)
> 			     X86_EFLAGS_IF | X86_EFLAGS_DF | X86_EFLAGS_OF |
> 			     X86_EFLAGS_IOPL | X86_EFLAGS_NT | X86_EFLAGS_RF |
> 			     X86_EFLAGS_AC | X86_EFLAGS_ID |
> -			     X86_EFLAGS_FIXED_BIT;
> +			     X86_EFLAGS_FIXED;
> 	unsigned long vm86_mask = X86_EFLAGS_VM | X86_EFLAGS_VIF |
> 				  X86_EFLAGS_VIP;
> 
> @@ -2072,7 +2072,7 @@ static int emulate_iret_real(struct x86_emulate_ctxt *ctxt)
> 	}
> 
> 	ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */
> -	ctxt->eflags |= X86_EFLAGS_FIXED_BIT;
> +	ctxt->eflags |= X86_EFLAGS_FIXED;
> 	ctxt->ops->set_nmi_mask(ctxt, false);
> 
> 	return rc;
> @@ -2390,7 +2390,7 @@ static int em_syscall(struct x86_emulate_ctxt *ctxt)
> 
> 		ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data);
> 		ctxt->eflags &= ~msr_data;
> -		ctxt->eflags |= X86_EFLAGS_FIXED_BIT;
> +		ctxt->eflags |= X86_EFLAGS_FIXED;
> #endif
> 	} else {
> 		/* legacy mode */
> -- 
> 1.7.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/