x86/vmware: Add basic paravirt ops support

Add basic paravirt support:

 1. Set pv_info.name to "VMware hypervisor" to have proper boot log message
	Booting paravirtualized kernel on VMware hypervisor
    instead of "... on bare hardware"

 2. Set pv_cpu_ops.io_delay() to empty function - paravirt_noop() to
    avoid vm-exits on IO delays because io delays they are not required.

Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Acked-by: Alok N Kataria <akataria@vmware.com>
Cc: linux-doc@vger.kernel.org
Cc: pv-drivers@vmware.com
Cc: corbet@lwn.net
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20161028075432.90579-3-amakhalov@vmware.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 480790f..098a524 100644 (file)
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -61,6 +61,16 @@ static unsigned long vmware_get_tsc_khz(void)
        return vmware_tsc_khz;
 }
 
+#ifdef CONFIG_PARAVIRT
+static void __init vmware_paravirt_ops_setup(void)
+{
+       pv_info.name = "VMware hypervisor";
+       pv_cpu_ops.io_delay = paravirt_nop;
+}
+#else
+#define vmware_paravirt_ops_setup() do {} while (0)
+#endif
+
 static void __init vmware_platform_setup(void)
 {
        uint32_t eax, ebx, ecx, edx;
@@ -94,6 +104,8 @@ static void __init vmware_platform_setup(void)
        } else {
                pr_warn("Failed to get TSC freq from the hypervisor\n");
        }
+
+       vmware_paravirt_ops_setup();
 }
 
 /*