[tip:x86/platform] x86/vmware: Add basic paravirt ops support

[tip-bot for Alexey Makhalov]

Commit-ID:  91d1e54ebd1615d216b7f57324a5e69166a344e0
Gitweb:     http://git.kernel.org/tip/91d1e54ebd1615d216b7f57324a5e69166a344e0
Author:     Alexey Makhalov <amakhalov@xxxxxxxxxx>
AuthorDate: Fri, 28 Oct 2016 00:54:31 -0700
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Sun, 30 Oct 2016 08:57:07 +0100

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@xxxxxxxxxx>
Acked-by: Alok N Kataria <akataria@xxxxxxxxxx>
Cc: linux-doc@xxxxxxxxxxxxxxx
Cc: pv-drivers@xxxxxxxxxx
Cc: corbet@xxxxxxx
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20161028075432.90579-3-amakhalov@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
 arch/x86/kernel/cpu/vmware.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 480790f..098a524 100644
--- 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();
 }
 
 /*