Re: [libvirt] [PATCH] cpu: Add recently added cpu feature flags.

On 10/24/2012 03:56 PM, Peter Krempa wrote: > Qemu has added some new feature flags. This patch adds them to libvirt. > > The new features are for the cpuid function 0x7 that takes an argument > in the ecx register. Currently only 0x0 is used as the argument so I was > lazy and I just clear the registers to 0 before calling cpuid. In future > when there maybe will be some other possible arguments, we will need to > improve the cpu detection code to take this into account. > --- > The qemu flag definiton can be found at: > http://git.qemu.org/?p=qemu.git;a=blob;f=target-i386/cpu.c;h=f3708e63b765... > --- > src/cpu/cpu_map.xml | 12 ++++++++++++ > src/cpu/cpu_x86.c | 8 +++++++- > 2 files changed, 19 insertions(+), 1 deletion(-) >

> diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c > index 7cd67b8..f54c3df 100644 > --- a/src/cpu/cpu_x86.c > +++ b/src/cpu/cpu_x86.c > @@ -1539,7 +1539,10 @@ static inline void > cpuidCall(struct cpuX86cpuid *cpuid) > { > # if __x86_64__ > - asm("cpuid" > + asm("xor %%ebx, %%ebx;" /* clear the other registers as some cpuid */ > + "xor %%ecx, %%ecx;" /* functions may use them as additional */ > + "xor %%edx, %%edx;" /* arguments */ > + "cpuid" Even though it doesn't change anything, this is the only line not having a semicolon at the end (and we have it in the "else" part), so if you want, you can make it a bit shinier and put it here as well ;)