From: Andrew Cooper Date: Tue, 19 Apr 2016 17:27:05 +0000 (+0100) Subject: tools/libxc: Correct use of X86_XSS_MASK in guest xstate generation X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~1273 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=4e4689e74d012b737bbca820cfe52c689c7d9cef;p=xen.git tools/libxc: Correct use of X86_XSS_MASK in guest xstate generation c/s 75f9455e "tools/libxc: Calculate xstate cpuid leaf from guest information" incorrectly inverted the shift and mask when using X86_XSS_MASK. Luckily, the mask is currently zero, avoiding incorrect calculations. While adjusting this, use an explcit uint32_t cast rather than masking against 0xffffffff. Signed-off-by: Andrew Cooper Acked-by: Wei Liu Release-acked-by: Wei Liu --- diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c index 6d14904c17..84f4e0810b 100644 --- a/tools/libxc/xc_cpuid_x86.c +++ b/tools/libxc/xc_cpuid_x86.c @@ -460,7 +460,7 @@ static void xc_cpuid_config_xsave(xc_interface *xch, { case 0: /* EAX: low 32bits of xfeature_enabled_mask */ - regs[0] = guest_xfeature_mask & 0xFFFFFFFF; + regs[0] = (uint32_t)guest_xfeature_mask; /* EDX: high 32bits of xfeature_enabled_mask */ regs[3] = guest_xfeature_mask >> 32; /* ECX: max size required by all HW features */ @@ -487,8 +487,8 @@ static void xc_cpuid_config_xsave(xc_interface *xch, if ( test_bit(X86_FEATURE_XSAVES, info->featureset) ) { - regs[2] = guest_xfeature_mask & X86_XSS_MASK & 0xFFFFFFFF; - regs[3] = (guest_xfeature_mask >> 32) & X86_XSS_MASK; + regs[2] = (uint32_t)(guest_xfeature_mask & X86_XSS_MASK); + regs[3] = (guest_xfeature_mask & X86_XSS_MASK) >> 32; } else regs[2] = regs[3] = 0;