Re: [Xen-devel] Side channel attack

2016-04-15 Thread Mihai Donțu
On Fri, 15 Apr 2016 15:49:20 +0800 Zakirasafi wrote: > The following code is for side channel attack on xen hypevisor. In this > code I am having problem in understanding the highlighted red line. In the > line what ".byte 15, byte 49" do??? You can use this trick in the future: $ printf

Re: [Xen-devel] Side channel attack

2016-04-15 Thread liuweijie
Hi Zakirasafi, > unsigned int timestamp(void) > { > unsigned int bottom; > unsigned int top; > *asm volatile(".byte 15;.byte 49" : "=a"(bottom),"=d"(top)); return bottom;* > } It is ‘RDTSC’ instruction. Besides, I am happy that someone is also working on side channel attack on Xen. Maybe we

Re: [Xen-devel] Side channel attack

2016-04-15 Thread Wei Liu
Hello Please don't post HTML mails. On Fri, Apr 15, 2016 at 03:49:20PM +0800, Zakirasafi wrote: > Dear All > The following code is for side channel attack on xen hypevisor. In this > code I am having problem in understanding the highlighted red line. In the > line what ".byte 15, byte 49" do???

[Xen-devel] Side channel attack

2016-04-15 Thread Zakirasafi
Dear All The following code is for side channel attack on xen hypevisor. In this code I am having problem in understanding the highlighted red line. In the line what ".byte 15, byte 49" do??? #include #include #include #include unsigned int timestamp(void) { unsigned int bottom; unsigned