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[PATCH v3 00/11] x86: xen cpuid() cleanup

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  [PATCH v3 00/11] x86: xen cpuid() cleanup Juergen Gross <jgross@suse.com> - 2017-04-18 08:40 +0200
    [PATCH v3 06/11] x86/xen: use capabilities instead of fake cpuid values for acpi Juergen Gross <jgross@suse.com> - 2017-04-18 08:40 +0200
    [PATCH v3 03/11] x86/xen: use capabilities instead of fake cpuid values for aperf Juergen Gross <jgross@suse.com> - 2017-04-18 08:40 +0200
    [PATCH v3 11/11] x86/cpu: remove hypervisor specific set_cpu_features Juergen Gross <jgross@suse.com> - 2017-04-18 08:40 +0200
    [PATCH v3 01/11] xen: set cpu capabilities from xen_start_kernel() Juergen Gross <jgross@suse.com> - 2017-04-18 08:40 +0200

#1625067 — [PATCH v3 00/11] x86: xen cpuid() cleanup

Reduce special casing of xen_cpuid() by using cpu capabilities instead
of faked cpuid nodes.

This cleanup enables us remove the hypervisor specific set_cpu_features
callback as the same effect can be reached via
setup_[clear|force]_cpu_cap().

Removing the rest faked nodes from xen_cpuid() requires some more work
as the remaining cases (mwait leafs and extended topology info) have
to be handled at the consumer sides of this information.

Changes in V3:
- rewrite patch 9 (xsave) to use xgetbv instruction to test for osxsave
  availability (Andrew Cooper)

Changes in V2:
- added several features to this scheme
- removed hypervisor specific set_cpu_features() callbacks

Cc: Alok Kataria <akataria@vmware.com> 
Cc: Thomas Gleixner <tglx@linutronix.de> 
Cc: Ingo Molnar <mingo@redhat.com> 
Cc: "H. Peter Anvin" <hpa@zytor.com> 
Cc: x86@kernel.org 
Cc: virtualization@lists.linux-foundation.org

Juergen Gross (11):
  xen: set cpu capabilities from xen_start_kernel()
  x86/xen: don't indicate DCA support in pv domains
  x86/xen: use capabilities instead of fake cpuid values for aperf
  x86/xen: use capabilities instead of fake cpuid values for mtrr
  x86/xen: use capabilities instead of fake cpuid values for acc
  x86/xen: use capabilities instead of fake cpuid values for acpi
  x86/xen: use capabilities instead of fake cpuid values for mwait
  x86/xen: use capabilities instead of fake cpuid values for x2apic
  x86/xen: use capabilities instead of fake cpuid values for xsave
  vmware: set cpu capabilities during platform initialization
  x86/cpu: remove hypervisor specific set_cpu_features

 arch/x86/include/asm/hypervisor.h |  5 ---
 arch/x86/kernel/cpu/common.c      |  1 -
 arch/x86/kernel/cpu/hypervisor.c  |  8 ----
 arch/x86/kernel/cpu/vmware.c      | 39 ++++++++--------
 arch/x86/xen/enlighten_pv.c       | 95 +++++++++++++++++----------------------
 5 files changed, 61 insertions(+), 87 deletions(-)

-- 
2.12.0

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#1625068 — [PATCH v3 06/11] x86/xen: use capabilities instead of fake cpuid values for acpi

When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the acpi feature is indicated as not
being present by special casing the related cpuid leaf in case we
are not the initial domain.

Instead of delivering fake cpuid values clear the cpu capability bit
for acpi instead.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 arch/x86/xen/enlighten_pv.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 53fe97bd720f..3196961862bc 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -165,7 +165,6 @@ xen_running_on_version_or_later(unsigned int major, unsigned int minor)
 	return false;
 }
 
-static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
 
 static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
@@ -177,7 +176,6 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 {
 	unsigned maskebx = ~0;
 	unsigned maskecx = ~0;
-	unsigned maskedx = ~0;
 	unsigned setecx = 0;
 	/*
 	 * Mask out inconvenient features, to try and disable as many
@@ -187,7 +185,6 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 	case 1:
 		maskecx = cpuid_leaf1_ecx_mask;
 		setecx = cpuid_leaf1_ecx_set_mask;
-		maskedx = cpuid_leaf1_edx_mask;
 		break;
 
 	case CPUID_MWAIT_LEAF:
@@ -214,7 +211,6 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 	*bx &= maskebx;
 	*cx &= maskecx;
 	*cx |= setecx;
-	*dx &= maskedx;
 }
 STACK_FRAME_NON_STANDARD(xen_cpuid); /* XEN_EMULATE_PREFIX */
 
@@ -294,10 +290,6 @@ static void __init xen_init_cpuid_mask(void)
 	unsigned int ax, bx, cx, dx;
 	unsigned int xsave_mask;
 
-	if (!xen_initial_domain())
-		cpuid_leaf1_edx_mask &=
-			~((1 << X86_FEATURE_ACPI));  /* disable ACPI */
-
 	cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32));
 
 	ax = 1;
@@ -323,6 +315,9 @@ static void __init xen_init_capabilities(void)
 	setup_clear_cpu_cap(X86_FEATURE_APERFMPERF);
 	setup_clear_cpu_cap(X86_FEATURE_MTRR);
 	setup_clear_cpu_cap(X86_FEATURE_ACC);
+
+	if (!xen_initial_domain())
+		setup_clear_cpu_cap(X86_FEATURE_ACPI);
 }
 
 static void xen_set_debugreg(int reg, unsigned long val)
-- 
2.12.0

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#1625069 — [PATCH v3 03/11] x86/xen: use capabilities instead of fake cpuid values for aperf

When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the aperf/mperf feature is indicated
as not being present by special casing the related cpuid leaf.

Instead of delivering fake cpuid values clear the cpu capability bit
for aperf/mperf instead.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 arch/x86/xen/enlighten_pv.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index bd69868909b4..4c8cd7278189 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -165,9 +165,6 @@ xen_running_on_version_or_later(unsigned int major, unsigned int minor)
 	return false;
 }
 
-#define CPUID_THERM_POWER_LEAF 6
-#define APERFMPERF_PRESENT 0
-
 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
 
@@ -201,11 +198,6 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
 		*dx = cpuid_leaf5_edx_val;
 		return;
 
-	case CPUID_THERM_POWER_LEAF:
-		/* Disabling APERFMPERF for kernel usage */
-		maskecx = ~(1 << APERFMPERF_PRESENT);
-		break;
-
 	case 0xb:
 		/* Suppress extended topology stuff */
 		maskebx = 0;
@@ -332,6 +324,7 @@ static void __init xen_init_capabilities(void)
 	setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
 	setup_force_cpu_cap(X86_FEATURE_XENPV);
 	setup_clear_cpu_cap(X86_FEATURE_DCA);
+	setup_clear_cpu_cap(X86_FEATURE_APERFMPERF);
 }
 
 static void xen_set_debugreg(int reg, unsigned long val)
-- 
2.12.0

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#1625070 — [PATCH v3 11/11] x86/cpu: remove hypervisor specific set_cpu_features

There is no user of x86_hyper->set_cpu_features() any more. Remove it.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 arch/x86/include/asm/hypervisor.h | 5 -----
 arch/x86/kernel/cpu/common.c      | 1 -
 arch/x86/kernel/cpu/hypervisor.c  | 8 --------
 3 files changed, 14 deletions(-)

diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h
index 6f7545c6e9cf..21126155a739 100644
--- a/arch/x86/include/asm/hypervisor.h
+++ b/arch/x86/include/asm/hypervisor.h
@@ -35,9 +35,6 @@ struct hypervisor_x86 {
 	/* Detection routine */
 	uint32_t	(*detect)(void);
 
-	/* Adjust CPU feature bits (run once per CPU) */
-	void		(*set_cpu_features)(struct cpuinfo_x86 *);
-
 	/* Platform setup (run once per boot) */
 	void		(*init_platform)(void);
 
@@ -57,12 +54,10 @@ extern const struct hypervisor_x86 x86_hyper_xen_pv;
 extern const struct hypervisor_x86 x86_hyper_xen_hvm;
 extern const struct hypervisor_x86 x86_hyper_kvm;
 
-extern void init_hypervisor(struct cpuinfo_x86 *c);
 extern void init_hypervisor_platform(void);
 extern bool hypervisor_x2apic_available(void);
 extern void hypervisor_pin_vcpu(int cpu);
 #else
-static inline void init_hypervisor(struct cpuinfo_x86 *c) { }
 static inline void init_hypervisor_platform(void) { }
 static inline bool hypervisor_x2apic_available(void) { return false; }
 #endif /* CONFIG_HYPERVISOR_GUEST */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8ee32119144d..c8b39870f33e 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1149,7 +1149,6 @@ static void identify_cpu(struct cpuinfo_x86 *c)
 	detect_ht(c);
 #endif
 
-	init_hypervisor(c);
 	x86_init_rdrand(c);
 	x86_init_cache_qos(c);
 	setup_pku(c);
diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index ce6fcc30f2ad..4fa90006ac68 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -63,12 +63,6 @@ detect_hypervisor_vendor(void)
 		pr_info("Hypervisor detected: %s\n", x86_hyper->name);
 }
 
-void init_hypervisor(struct cpuinfo_x86 *c)
-{
-	if (x86_hyper && x86_hyper->set_cpu_features)
-		x86_hyper->set_cpu_features(c);
-}
-
 void __init init_hypervisor_platform(void)
 {
 
@@ -77,8 +71,6 @@ void __init init_hypervisor_platform(void)
 	if (!x86_hyper)
 		return;
 
-	init_hypervisor(&boot_cpu_data);
-
 	if (x86_hyper->init_platform)
 		x86_hyper->init_platform();
 }
-- 
2.12.0

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#1625071 — [PATCH v3 01/11] xen: set cpu capabilities from xen_start_kernel()

There is no need to set the same capabilities for each cpu
individually. This can easily be done for all cpus when starting the
kernel.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 arch/x86/xen/enlighten_pv.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index b226f67fb741..6dc922e3848a 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -327,6 +327,12 @@ static void __init xen_init_cpuid_mask(void)
 		cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
 }
 
+static void __init xen_init_capabilities(void)
+{
+	setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
+	setup_force_cpu_cap(X86_FEATURE_XENPV);
+}
+
 static void xen_set_debugreg(int reg, unsigned long val)
 {
 	HYPERVISOR_set_debugreg(reg, val);
@@ -1318,6 +1324,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
 
 	xen_init_irq_ops();
 	xen_init_cpuid_mask();
+	xen_init_capabilities();
 
 #ifdef CONFIG_X86_LOCAL_APIC
 	/*
@@ -1506,16 +1513,9 @@ static uint32_t __init xen_platform_pv(void)
 	return 0;
 }
 
-static void xen_set_cpu_features(struct cpuinfo_x86 *c)
-{
-	clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
-	set_cpu_cap(c, X86_FEATURE_XENPV);
-}
-
 const struct hypervisor_x86 x86_hyper_xen_pv = {
 	.name                   = "Xen PV",
 	.detect                 = xen_platform_pv,
-	.set_cpu_features       = xen_set_cpu_features,
 	.pin_vcpu               = xen_pin_vcpu,
 };
 EXPORT_SYMBOL(x86_hyper_xen_pv);
-- 
2.12.0

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