Re: [Qemu-devel] [PATCH] x86: only allow real mode to access 32bit without LMA

2013-12-07 Thread Michael Tokarev
06.12.2013 16:52, Alexander Graf wrote: > When we're running in non-64bit mode with qemu-system-x86_64 we can > still end up with virtual addresses that are above the 32bit boundary > if a segment offset is set up. > > GNU Hurd does exactly that. It sets the segment offset to 0x8000 and > puts

Re: [Qemu-devel] [PATCH] x86: only allow real mode to access 32bit without LMA

2013-12-06 Thread Stefan Weil
Am 06.12.2013 19:48, schrieb Michael Tokarev: > 06.12.2013 16:52, Alexander Graf wrote: >> When we're running in non-64bit mode with qemu-system-x86_64 we can >> still end up with virtual addresses that are above the 32bit boundary >> if a segment offset is set up. >> >> GNU Hurd does exactly that.

Re: [Qemu-devel] [PATCH] x86: only allow real mode to access 32bit without LMA

2013-12-06 Thread Michael Tokarev
06.12.2013 16:52, Alexander Graf wrote: > When we're running in non-64bit mode with qemu-system-x86_64 we can > still end up with virtual addresses that are above the 32bit boundary > if a segment offset is set up. > > GNU Hurd does exactly that. It sets the segment offset to 0x8000 and > puts

Re: [Qemu-devel] [PATCH] x86: only allow real mode to access 32bit without LMA

2013-12-06 Thread Richard Henderson
On 12/07/2013 01:52 AM, Alexander Graf wrote: > When we're running in non-64bit mode with qemu-system-x86_64 we can > still end up with virtual addresses that are above the 32bit boundary > if a segment offset is set up. > > GNU Hurd does exactly that. It sets the segment offset to 0x8000 and

[Qemu-devel] [PATCH] x86: only allow real mode to access 32bit without LMA

2013-12-06 Thread Alexander Graf
When we're running in non-64bit mode with qemu-system-x86_64 we can still end up with virtual addresses that are above the 32bit boundary if a segment offset is set up. GNU Hurd does exactly that. It sets the segment offset to 0x8000 and puts its EIP value to 0x8xxx to access low memory.