[PATCH 1/2] x86/xen: don't indicate DCA support in pv domains

From: Juergen Gross
Date: Fri Feb 17 2017 - 02:37:13 EST


Xen doesn't support DCA (direct cache access) for pv domains. Clear
the corresponding capability indicator.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
arch/x86/xen/enlighten.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 51ef952..83399ce 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -461,6 +461,9 @@ static void __init xen_init_cpuid_mask(void)
cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
if (xen_check_mwait())
cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
+
+ /* Disable DCA feature. */
+ setup_clear_cpu_cap(X86_FEATURE_DCA);
}

static void xen_set_debugreg(int reg, unsigned long val)
--
2.10.2