[GIT PULL] KVM/arm64 fixes for 5.11, take #1

[GIT PULL] KVM/arm64 fixes for 5.11, take #1

[Marc Zyngier]

Hi Paolo,

Happy New Year!

Here's a first set of fixes for 5.11, most of which are just
cleanups. I may have some more meaty stuff next week, but let's ease
back into it as gently as possible...

Please pull,

	M.

The following changes since commit 3a514592b698588326924625b6948a10c35fadd5:

  Merge remote-tracking branch 'origin/kvm-arm64/psci-relay' into kvmarm-master/next (2020-12-09 10:00:24 +0000)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git tags/kvmarm-fixes-5.11-1

for you to fetch changes up to 45ba7b195a369f35cb39094fdb32efe5908b34ad:

  arm64: cpufeature: remove non-exist CONFIG_KVM_ARM_HOST (2021-01-05 13:22:07 +0000)

----------------------------------------------------------------
KVM/arm64 fixes for 5.11, take #1

- VM init cleanups
- PSCI relay cleanups
- Kill CONFIG_KVM_ARM_PMU
- Fixup __init annotations
- Fixup reg_to_encoding()
- Fix spurious PMCR_EL0 access

----------------------------------------------------------------
Alexandru Elisei (5):
      KVM: Documentation: Add arm64 KVM_RUN error codes
      KVM: arm64: arch_timer: Remove VGIC initialization check
      KVM: arm64: Move double-checked lock to kvm_vgic_map_resources()
      KVM: arm64: Update comment in kvm_vgic_map_resources()
      KVM: arm64: Remove redundant call to kvm_pmu_vcpu_reset()

David Brazdil (6):
      KVM: arm64: Prevent use of invalid PSCI v0.1 function IDs
      KVM: arm64: Use lm_alias in nVHE-only VA conversion
      KVM: arm64: Skip computing hyp VA layout for VHE
      KVM: arm64: Minor cleanup of hyp variables used in host
      KVM: arm64: Remove unused includes in psci-relay.c
      KVM: arm64: Move skip_host_instruction to adjust_pc.h

Marc Zyngier (6):
      KVM: arm64: Don't access PMCR_EL0 when no PMU is available
      KVM: arm64: Declutter host PSCI 0.1 handling
      KVM: arm64: Consolidate dist->ready setting into kvm_vgic_map_resources()
      KVM: arm64: Fix hyp_cpu_pm_{init,exit} __init annotation
      KVM: arm64: Remove spurious semicolon in reg_to_encoding()
      KVM: arm64: Replace KVM_ARM_PMU with HW_PERF_EVENTS

Shannon Zhao (1):
      arm64: cpufeature: remove non-exist CONFIG_KVM_ARM_HOST

 Documentation/virt/kvm/api.rst             |  9 ++++-
 arch/arm64/include/asm/kvm_host.h          | 23 ++++++++++++
 arch/arm64/kernel/cpufeature.c             |  2 +-
 arch/arm64/kernel/smp.c                    |  2 +-
 arch/arm64/kvm/Kconfig                     |  8 ----
 arch/arm64/kvm/Makefile                    |  2 +-
 arch/arm64/kvm/arch_timer.c                |  7 ++--
 arch/arm64/kvm/arm.c                       | 32 +++++++++-------
 arch/arm64/kvm/hyp/include/hyp/adjust_pc.h |  9 +++++
 arch/arm64/kvm/hyp/nvhe/hyp-main.c         | 12 +-----
 arch/arm64/kvm/hyp/nvhe/hyp-smp.c          |  6 +--
 arch/arm64/kvm/hyp/nvhe/psci-relay.c       | 59 +++++++++++-------------------
 arch/arm64/kvm/pmu-emul.c                  |  2 -
 arch/arm64/kvm/sys_regs.c                  |  6 ++-
 arch/arm64/kvm/va_layout.c                 |  7 ++--
 arch/arm64/kvm/vgic/vgic-init.c            | 11 +++++-
 arch/arm64/kvm/vgic/vgic-v2.c              | 20 +++-------
 arch/arm64/kvm/vgic/vgic-v3.c              | 21 +++--------
 include/kvm/arm_pmu.h                      |  2 +-
 19 files changed, 122 insertions(+), 118 deletions(-)

[PATCH 01/18] KVM: arm64: Don't access PMCR_EL0 when no PMU is available

[Marc Zyngier]

We reset the guest's view of PMCR_EL0 unconditionally, based on
the host's view of this register. It is however legal for an
implementation not to provide any PMU, resulting in an UNDEF.

The obvious fix is to skip the reset of this shadow register
when no PMU is available, sidestepping the issue entirely.
If no PMU is available, the guest is not able to request
a virtual PMU anyway, so not doing nothing is the right thing
to do!

It is unlikely that this bug can hit any HW implementation
though, as they all provide a PMU. It has been found using nested
virt with the host KVM not implementing the PMU itself.

Fixes: ab9468340d2bc ("arm64: KVM: Add access handler for PMCR register")
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201210083059.1277162-1-maz@kernel.org
---
 arch/arm64/kvm/sys_regs.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 3313dedfa505..d46e7f706cb0 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -594,6 +594,10 @@ static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 {
 	u64 pmcr, val;
 
+	/* No PMU available, PMCR_EL0 may UNDEF... */
+	if (!kvm_arm_support_pmu_v3())
+		return;
+
 	pmcr = read_sysreg(pmcr_el0);
 	/*
 	 * Writable bits of PMCR_EL0 (ARMV8_PMU_PMCR_MASK) are reset to UNKNOWN
-- 
2.29.2

[PATCH 02/18] KVM: arm64: Prevent use of invalid PSCI v0.1 function IDs

[Marc Zyngier]

From: David Brazdil <dbrazdil@google.com>

PSCI driver exposes a struct containing the PSCI v0.1 function IDs
configured in the DT. However, the struct does not convey the
information whether these were set from DT or contain the default value
zero. This could be a problem for PSCI proxy in KVM protected mode.

Extend config passed to KVM with a bit mask with individual bits set
depending on whether the corresponding function pointer in psci_ops is
set, eg. set bit for PSCI_CPU_SUSPEND if psci_ops.cpu_suspend != NULL.

Previously config was split into multiple global variables. Put
everything into a single struct for convenience.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201208142452.87237-2-dbrazdil@google.com
---
 arch/arm64/include/asm/kvm_host.h    | 20 +++++++++++
 arch/arm64/kvm/arm.c                 | 14 +++++---
 arch/arm64/kvm/hyp/nvhe/psci-relay.c | 53 +++++++++++++++++++++-------
 3 files changed, 70 insertions(+), 17 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 11beda85ee7e..828d50d40dc2 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -17,6 +17,7 @@
 #include <linux/jump_label.h>
 #include <linux/kvm_types.h>
 #include <linux/percpu.h>
+#include <linux/psci.h>
 #include <asm/arch_gicv3.h>
 #include <asm/barrier.h>
 #include <asm/cpufeature.h>
@@ -240,6 +241,25 @@ struct kvm_host_data {
 	struct kvm_pmu_events pmu_events;
 };
 
+#define KVM_HOST_PSCI_0_1_CPU_SUSPEND	BIT(0)
+#define KVM_HOST_PSCI_0_1_CPU_ON	BIT(1)
+#define KVM_HOST_PSCI_0_1_CPU_OFF	BIT(2)
+#define KVM_HOST_PSCI_0_1_MIGRATE	BIT(3)
+
+struct kvm_host_psci_config {
+	/* PSCI version used by host. */
+	u32 version;
+
+	/* Function IDs used by host if version is v0.1. */
+	struct psci_0_1_function_ids function_ids_0_1;
+
+	/* Bitmask of functions enabled for v0.1, bits KVM_HOST_PSCI_0_1_*. */
+	unsigned int enabled_functions_0_1;
+};
+
+extern struct kvm_host_psci_config kvm_nvhe_sym(kvm_host_psci_config);
+#define kvm_host_psci_config CHOOSE_NVHE_SYM(kvm_host_psci_config)
+
 struct vcpu_reset_state {
 	unsigned long	pc;
 	unsigned long	r0;
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 6e637d2b4cfb..6a2f4e01b04f 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -66,8 +66,6 @@ static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);
 DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
 
 extern u64 kvm_nvhe_sym(__cpu_logical_map)[NR_CPUS];
-extern u32 kvm_nvhe_sym(kvm_host_psci_version);
-extern struct psci_0_1_function_ids kvm_nvhe_sym(kvm_host_psci_0_1_function_ids);
 
 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 {
@@ -1618,8 +1616,16 @@ static bool init_psci_relay(void)
 		return false;
 	}
 
-	kvm_nvhe_sym(kvm_host_psci_version) = psci_ops.get_version();
-	kvm_nvhe_sym(kvm_host_psci_0_1_function_ids) = get_psci_0_1_function_ids();
+	kvm_host_psci_config.version = psci_ops.get_version();
+
+	if (kvm_host_psci_config.version == PSCI_VERSION(0, 1)) {
+		kvm_host_psci_config.function_ids_0_1 = get_psci_0_1_function_ids();
+		kvm_host_psci_config.enabled_functions_0_1 =
+			(psci_ops.cpu_suspend ? KVM_HOST_PSCI_0_1_CPU_SUSPEND : 0) |
+			(psci_ops.cpu_off ? KVM_HOST_PSCI_0_1_CPU_OFF : 0) |
+			(psci_ops.cpu_on ? KVM_HOST_PSCI_0_1_CPU_ON : 0) |
+			(psci_ops.migrate ? KVM_HOST_PSCI_0_1_MIGRATE : 0);
+	}
 	return true;
 }
 
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index 08dc9de69314..0d6f4aa39621 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -22,9 +22,8 @@ void kvm_hyp_cpu_resume(unsigned long r0);
 void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt);
 
 /* Config options set by the host. */
-__ro_after_init u32 kvm_host_psci_version;
-__ro_after_init struct psci_0_1_function_ids kvm_host_psci_0_1_function_ids;
-__ro_after_init s64 hyp_physvirt_offset;
+struct kvm_host_psci_config __ro_after_init kvm_host_psci_config;
+s64 __ro_after_init hyp_physvirt_offset;
 
 #define __hyp_pa(x) ((phys_addr_t)((x)) + hyp_physvirt_offset)
 
@@ -54,12 +53,41 @@ static u64 get_psci_func_id(struct kvm_cpu_context *host_ctxt)
 	return func_id;
 }
 
+static inline bool is_psci_0_1_function_enabled(unsigned int fn_bit)
+{
+	return kvm_host_psci_config.enabled_functions_0_1 & fn_bit;
+}
+
+static inline bool is_psci_0_1_cpu_suspend(u64 func_id)
+{
+	return is_psci_0_1_function_enabled(KVM_HOST_PSCI_0_1_CPU_SUSPEND) &&
+	       (func_id == kvm_host_psci_config.function_ids_0_1.cpu_suspend);
+}
+
+static inline bool is_psci_0_1_cpu_on(u64 func_id)
+{
+	return is_psci_0_1_function_enabled(KVM_HOST_PSCI_0_1_CPU_ON) &&
+	       (func_id == kvm_host_psci_config.function_ids_0_1.cpu_on);
+}
+
+static inline bool is_psci_0_1_cpu_off(u64 func_id)
+{
+	return is_psci_0_1_function_enabled(KVM_HOST_PSCI_0_1_CPU_OFF) &&
+	       (func_id == kvm_host_psci_config.function_ids_0_1.cpu_off);
+}
+
+static inline bool is_psci_0_1_migrate(u64 func_id)
+{
+	return is_psci_0_1_function_enabled(KVM_HOST_PSCI_0_1_MIGRATE) &&
+	       (func_id == kvm_host_psci_config.function_ids_0_1.migrate);
+}
+
 static bool is_psci_0_1_call(u64 func_id)
 {
-	return (func_id == kvm_host_psci_0_1_function_ids.cpu_suspend) ||
-	       (func_id == kvm_host_psci_0_1_function_ids.cpu_on) ||
-	       (func_id == kvm_host_psci_0_1_function_ids.cpu_off) ||
-	       (func_id == kvm_host_psci_0_1_function_ids.migrate);
+	return is_psci_0_1_cpu_suspend(func_id) ||
+	       is_psci_0_1_cpu_on(func_id) ||
+	       is_psci_0_1_cpu_off(func_id) ||
+	       is_psci_0_1_migrate(func_id);
 }
 
 static bool is_psci_0_2_call(u64 func_id)
@@ -71,7 +99,7 @@ static bool is_psci_0_2_call(u64 func_id)
 
 static bool is_psci_call(u64 func_id)
 {
-	switch (kvm_host_psci_version) {
+	switch (kvm_host_psci_config.version) {
 	case PSCI_VERSION(0, 1):
 		return is_psci_0_1_call(func_id);
 	default:
@@ -248,12 +276,11 @@ asmlinkage void __noreturn kvm_host_psci_cpu_entry(bool is_cpu_on)
 
 static unsigned long psci_0_1_handler(u64 func_id, struct kvm_cpu_context *host_ctxt)
 {
-	if ((func_id == kvm_host_psci_0_1_function_ids.cpu_off) ||
-	    (func_id == kvm_host_psci_0_1_function_ids.migrate))
+	if (is_psci_0_1_cpu_off(func_id) || is_psci_0_1_migrate(func_id))
 		return psci_forward(host_ctxt);
-	else if (func_id == kvm_host_psci_0_1_function_ids.cpu_on)
+	else if (is_psci_0_1_cpu_on(func_id))
 		return psci_cpu_on(func_id, host_ctxt);
-	else if (func_id == kvm_host_psci_0_1_function_ids.cpu_suspend)
+	else if (is_psci_0_1_cpu_suspend(func_id))
 		return psci_cpu_suspend(func_id, host_ctxt);
 	else
 		return PSCI_RET_NOT_SUPPORTED;
@@ -304,7 +331,7 @@ bool kvm_host_psci_handler(struct kvm_cpu_context *host_ctxt)
 	if (!is_psci_call(func_id))
 		return false;
 
-	switch (kvm_host_psci_version) {
+	switch (kvm_host_psci_config.version) {
 	case PSCI_VERSION(0, 1):
 		ret = psci_0_1_handler(func_id, host_ctxt);
 		break;
-- 
2.29.2

[PATCH 03/18] KVM: arm64: Use lm_alias in nVHE-only VA conversion

[Marc Zyngier]

From: David Brazdil <dbrazdil@google.com>

init_hyp_physvirt_offset() computes PA from a kernel VA. Conversion to
kernel linear-map is required first but the code used kvm_ksym_ref() for
this purpose. Under VHE that is a NOP and resulted in a runtime warning.
Replace kvm_ksym_ref with lm_alias.

Reported-by: Qian Cai <qcai@redhat.com>
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201208142452.87237-3-dbrazdil@google.com
---
 arch/arm64/kvm/va_layout.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index d8cc51bd60bf..914732b88c69 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -42,7 +42,7 @@ static void init_hyp_physvirt_offset(void)
 	u64 kern_va, hyp_va;
 
 	/* Compute the offset from the hyp VA and PA of a random symbol. */
-	kern_va = (u64)kvm_ksym_ref(__hyp_text_start);
+	kern_va = (u64)lm_alias(__hyp_text_start);
 	hyp_va = __early_kern_hyp_va(kern_va);
 	CHOOSE_NVHE_SYM(hyp_physvirt_offset) = (s64)__pa(kern_va) - (s64)hyp_va;
 }
-- 
2.29.2

[PATCH 04/18] KVM: arm64: Skip computing hyp VA layout for VHE

[Marc Zyngier]

From: David Brazdil <dbrazdil@google.com>

Computing the hyp VA layout is redundant when the kernel runs in EL2 and
hyp shares its VA mappings. Make calling kvm_compute_layout()
conditional on not just CONFIG_KVM but also !is_kernel_in_hyp_mode().

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201208142452.87237-4-dbrazdil@google.com
---
 arch/arm64/kernel/smp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 18e9727d3f64..4e585cc892e8 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -434,7 +434,7 @@ static void __init hyp_mode_check(void)
 			   "CPU: CPUs started in inconsistent modes");
 	else
 		pr_info("CPU: All CPU(s) started at EL1\n");
-	if (IS_ENABLED(CONFIG_KVM))
+	if (IS_ENABLED(CONFIG_KVM) && !is_kernel_in_hyp_mode())
 		kvm_compute_layout();
 }
 
-- 
2.29.2

[PATCH 05/18] KVM: arm64: Minor cleanup of hyp variables used in host

[Marc Zyngier]

From: David Brazdil <dbrazdil@google.com>

Small cleanup moving declarations of hyp-exported variables to
kvm_host.h and using macros to avoid having to refer to them with
kvm_nvhe_sym() in host.

No functional change intended.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201208142452.87237-5-dbrazdil@google.com
---
 arch/arm64/include/asm/kvm_host.h | 6 ++++++
 arch/arm64/kvm/arm.c              | 4 +---
 arch/arm64/kvm/hyp/nvhe/hyp-smp.c | 6 +++---
 arch/arm64/kvm/va_layout.c        | 5 ++---
 4 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 828d50d40dc2..bce2452b305c 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -260,6 +260,12 @@ struct kvm_host_psci_config {
 extern struct kvm_host_psci_config kvm_nvhe_sym(kvm_host_psci_config);
 #define kvm_host_psci_config CHOOSE_NVHE_SYM(kvm_host_psci_config)
 
+extern s64 kvm_nvhe_sym(hyp_physvirt_offset);
+#define hyp_physvirt_offset CHOOSE_NVHE_SYM(hyp_physvirt_offset)
+
+extern u64 kvm_nvhe_sym(hyp_cpu_logical_map)[NR_CPUS];
+#define hyp_cpu_logical_map CHOOSE_NVHE_SYM(hyp_cpu_logical_map)
+
 struct vcpu_reset_state {
 	unsigned long	pc;
 	unsigned long	r0;
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 6a2f4e01b04f..836ca763b91d 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -65,8 +65,6 @@ static bool vgic_present;
 static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);
 DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
 
-extern u64 kvm_nvhe_sym(__cpu_logical_map)[NR_CPUS];
-
 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 {
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
@@ -1602,7 +1600,7 @@ static void init_cpu_logical_map(void)
 	 * allow any other CPUs from the `possible` set to boot.
 	 */
 	for_each_online_cpu(cpu)
-		kvm_nvhe_sym(__cpu_logical_map)[cpu] = cpu_logical_map(cpu);
+		hyp_cpu_logical_map[cpu] = cpu_logical_map(cpu);
 }
 
 static bool init_psci_relay(void)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
index cbab0c6246e2..2997aa156d8e 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
@@ -14,14 +14,14 @@
  * Other CPUs should not be allowed to boot because their features were
  * not checked against the finalized system capabilities.
  */
-u64 __ro_after_init __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
+u64 __ro_after_init hyp_cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
 
 u64 cpu_logical_map(unsigned int cpu)
 {
-	if (cpu >= ARRAY_SIZE(__cpu_logical_map))
+	if (cpu >= ARRAY_SIZE(hyp_cpu_logical_map))
 		hyp_panic();
 
-	return __cpu_logical_map[cpu];
+	return hyp_cpu_logical_map[cpu];
 }
 
 unsigned long __hyp_per_cpu_offset(unsigned int cpu)
diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index 914732b88c69..70fcd6a12fe1 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -34,17 +34,16 @@ static u64 __early_kern_hyp_va(u64 addr)
 }
 
 /*
- * Store a hyp VA <-> PA offset into a hyp-owned variable.
+ * Store a hyp VA <-> PA offset into a EL2-owned variable.
  */
 static void init_hyp_physvirt_offset(void)
 {
-	extern s64 kvm_nvhe_sym(hyp_physvirt_offset);
 	u64 kern_va, hyp_va;
 
 	/* Compute the offset from the hyp VA and PA of a random symbol. */
 	kern_va = (u64)lm_alias(__hyp_text_start);
 	hyp_va = __early_kern_hyp_va(kern_va);
-	CHOOSE_NVHE_SYM(hyp_physvirt_offset) = (s64)__pa(kern_va) - (s64)hyp_va;
+	hyp_physvirt_offset = (s64)__pa(kern_va) - (s64)hyp_va;
 }
 
 /*
-- 
2.29.2

[PATCH 06/18] KVM: arm64: Remove unused includes in psci-relay.c

[Marc Zyngier]

From: David Brazdil <dbrazdil@google.com>

Minor cleanup removing unused includes.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201208142452.87237-6-dbrazdil@google.com
---
 arch/arm64/kvm/hyp/nvhe/psci-relay.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index 0d6f4aa39621..1f7237e45148 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -7,11 +7,8 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
-#include <kvm/arm_hypercalls.h>
 #include <linux/arm-smccc.h>
 #include <linux/kvm_host.h>
-#include <linux/psci.h>
-#include <kvm/arm_psci.h>
 #include <uapi/linux/psci.h>
 
 #include <nvhe/trap_handler.h>
-- 
2.29.2

[PATCH 07/18] KVM: arm64: Move skip_host_instruction to adjust_pc.h

[Marc Zyngier]

From: David Brazdil <dbrazdil@google.com>

Move function for skipping host instruction in the host trap handler to
a header file containing analogical helpers for guests.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201208142452.87237-7-dbrazdil@google.com
---
 arch/arm64/kvm/hyp/include/hyp/adjust_pc.h |  9 +++++++++
 arch/arm64/kvm/hyp/nvhe/hyp-main.c         | 12 ++----------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h b/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
index b1f60923a8fe..61716359035d 100644
--- a/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
+++ b/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
@@ -59,4 +59,13 @@ static inline void __adjust_pc(struct kvm_vcpu *vcpu)
 	}
 }
 
+/*
+ * Skip an instruction while host sysregs are live.
+ * Assumes host is always 64-bit.
+ */
+static inline void kvm_skip_host_instr(void)
+{
+	write_sysreg_el2(read_sysreg_el2(SYS_ELR) + 4, SYS_ELR);
+}
+
 #endif
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index bde658d51404..a906f9e2ff34 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -157,11 +157,6 @@ static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt)
 	__kvm_hyp_host_forward_smc(host_ctxt);
 }
 
-static void skip_host_instruction(void)
-{
-	write_sysreg_el2(read_sysreg_el2(SYS_ELR) + 4, SYS_ELR);
-}
-
 static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
 {
 	bool handled;
@@ -170,11 +165,8 @@ static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
 	if (!handled)
 		default_host_smc_handler(host_ctxt);
 
-	/*
-	 * Unlike HVC, the return address of an SMC is the instruction's PC.
-	 * Move the return address past the instruction.
-	 */
-	skip_host_instruction();
+	/* SMC was trapped, move ELR past the current PC. */
+	kvm_skip_host_instr();
 }
 
 void handle_trap(struct kvm_cpu_context *host_ctxt)
-- 
2.29.2

[PATCH 08/18] KVM: arm64: Declutter host PSCI 0.1 handling

[Marc Zyngier]

Although there is nothing wrong with the current host PSCI relay
implementation, we can clean it up and remove some of the helpers
that do not improve the overall readability of the legacy PSCI 0.1
handling.

Opportunity is taken to turn the bitmap into a set of booleans,
and creative use of preprocessor macros make init and check
more concise/readable.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_host.h    | 11 ++--
 arch/arm64/kvm/arm.c                 | 12 +++--
 arch/arm64/kvm/hyp/nvhe/psci-relay.c | 77 +++++++---------------------
 3 files changed, 30 insertions(+), 70 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index bce2452b305c..8fcfab0c2567 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -241,11 +241,6 @@ struct kvm_host_data {
 	struct kvm_pmu_events pmu_events;
 };
 
-#define KVM_HOST_PSCI_0_1_CPU_SUSPEND	BIT(0)
-#define KVM_HOST_PSCI_0_1_CPU_ON	BIT(1)
-#define KVM_HOST_PSCI_0_1_CPU_OFF	BIT(2)
-#define KVM_HOST_PSCI_0_1_MIGRATE	BIT(3)
-
 struct kvm_host_psci_config {
 	/* PSCI version used by host. */
 	u32 version;
@@ -253,8 +248,10 @@ struct kvm_host_psci_config {
 	/* Function IDs used by host if version is v0.1. */
 	struct psci_0_1_function_ids function_ids_0_1;
 
-	/* Bitmask of functions enabled for v0.1, bits KVM_HOST_PSCI_0_1_*. */
-	unsigned int enabled_functions_0_1;
+	bool psci_0_1_cpu_suspend_implemented;
+	bool psci_0_1_cpu_on_implemented;
+	bool psci_0_1_cpu_off_implemented;
+	bool psci_0_1_migrate_implemented;
 };
 
 extern struct kvm_host_psci_config kvm_nvhe_sym(kvm_host_psci_config);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 836ca763b91d..e207e4541f55 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1603,6 +1603,9 @@ static void init_cpu_logical_map(void)
 		hyp_cpu_logical_map[cpu] = cpu_logical_map(cpu);
 }
 
+#define init_psci_0_1_impl_state(config, what)	\
+	config.psci_0_1_ ## what ## _implemented = psci_ops.what
+
 static bool init_psci_relay(void)
 {
 	/*
@@ -1618,11 +1621,10 @@ static bool init_psci_relay(void)
 
 	if (kvm_host_psci_config.version == PSCI_VERSION(0, 1)) {
 		kvm_host_psci_config.function_ids_0_1 = get_psci_0_1_function_ids();
-		kvm_host_psci_config.enabled_functions_0_1 =
-			(psci_ops.cpu_suspend ? KVM_HOST_PSCI_0_1_CPU_SUSPEND : 0) |
-			(psci_ops.cpu_off ? KVM_HOST_PSCI_0_1_CPU_OFF : 0) |
-			(psci_ops.cpu_on ? KVM_HOST_PSCI_0_1_CPU_ON : 0) |
-			(psci_ops.migrate ? KVM_HOST_PSCI_0_1_MIGRATE : 0);
+		init_psci_0_1_impl_state(kvm_host_psci_config, cpu_suspend);
+		init_psci_0_1_impl_state(kvm_host_psci_config, cpu_on);
+		init_psci_0_1_impl_state(kvm_host_psci_config, cpu_off);
+		init_psci_0_1_impl_state(kvm_host_psci_config, migrate);
 	}
 	return true;
 }
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index 1f7237e45148..e3947846ffcb 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -43,48 +43,16 @@ struct psci_boot_args {
 static DEFINE_PER_CPU(struct psci_boot_args, cpu_on_args) = PSCI_BOOT_ARGS_INIT;
 static DEFINE_PER_CPU(struct psci_boot_args, suspend_args) = PSCI_BOOT_ARGS_INIT;
 
-static u64 get_psci_func_id(struct kvm_cpu_context *host_ctxt)
-{
-	DECLARE_REG(u64, func_id, host_ctxt, 0);
-
-	return func_id;
-}
-
-static inline bool is_psci_0_1_function_enabled(unsigned int fn_bit)
-{
-	return kvm_host_psci_config.enabled_functions_0_1 & fn_bit;
-}
-
-static inline bool is_psci_0_1_cpu_suspend(u64 func_id)
-{
-	return is_psci_0_1_function_enabled(KVM_HOST_PSCI_0_1_CPU_SUSPEND) &&
-	       (func_id == kvm_host_psci_config.function_ids_0_1.cpu_suspend);
-}
-
-static inline bool is_psci_0_1_cpu_on(u64 func_id)
-{
-	return is_psci_0_1_function_enabled(KVM_HOST_PSCI_0_1_CPU_ON) &&
-	       (func_id == kvm_host_psci_config.function_ids_0_1.cpu_on);
-}
-
-static inline bool is_psci_0_1_cpu_off(u64 func_id)
-{
-	return is_psci_0_1_function_enabled(KVM_HOST_PSCI_0_1_CPU_OFF) &&
-	       (func_id == kvm_host_psci_config.function_ids_0_1.cpu_off);
-}
-
-static inline bool is_psci_0_1_migrate(u64 func_id)
-{
-	return is_psci_0_1_function_enabled(KVM_HOST_PSCI_0_1_MIGRATE) &&
-	       (func_id == kvm_host_psci_config.function_ids_0_1.migrate);
-}
+#define	is_psci_0_1(what, func_id)					\
+	(kvm_host_psci_config.psci_0_1_ ## what ## _implemented &&	\
+	 (func_id) == kvm_host_psci_config.function_ids_0_1.what)
 
 static bool is_psci_0_1_call(u64 func_id)
 {
-	return is_psci_0_1_cpu_suspend(func_id) ||
-	       is_psci_0_1_cpu_on(func_id) ||
-	       is_psci_0_1_cpu_off(func_id) ||
-	       is_psci_0_1_migrate(func_id);
+	return (is_psci_0_1(cpu_suspend, func_id) ||
+		is_psci_0_1(cpu_on, func_id) ||
+		is_psci_0_1(cpu_off, func_id) ||
+		is_psci_0_1(migrate, func_id));
 }
 
 static bool is_psci_0_2_call(u64 func_id)
@@ -94,16 +62,6 @@ static bool is_psci_0_2_call(u64 func_id)
 	       (PSCI_0_2_FN64(0) <= func_id && func_id <= PSCI_0_2_FN64(31));
 }
 
-static bool is_psci_call(u64 func_id)
-{
-	switch (kvm_host_psci_config.version) {
-	case PSCI_VERSION(0, 1):
-		return is_psci_0_1_call(func_id);
-	default:
-		return is_psci_0_2_call(func_id);
-	}
-}
-
 static unsigned long psci_call(unsigned long fn, unsigned long arg0,
 			       unsigned long arg1, unsigned long arg2)
 {
@@ -273,14 +231,14 @@ asmlinkage void __noreturn kvm_host_psci_cpu_entry(bool is_cpu_on)
 
 static unsigned long psci_0_1_handler(u64 func_id, struct kvm_cpu_context *host_ctxt)
 {
-	if (is_psci_0_1_cpu_off(func_id) || is_psci_0_1_migrate(func_id))
+	if (is_psci_0_1(cpu_off, func_id) || is_psci_0_1(migrate, func_id))
 		return psci_forward(host_ctxt);
-	else if (is_psci_0_1_cpu_on(func_id))
+	if (is_psci_0_1(cpu_on, func_id))
 		return psci_cpu_on(func_id, host_ctxt);
-	else if (is_psci_0_1_cpu_suspend(func_id))
+	if (is_psci_0_1(cpu_suspend, func_id))
 		return psci_cpu_suspend(func_id, host_ctxt);
-	else
-		return PSCI_RET_NOT_SUPPORTED;
+
+	return PSCI_RET_NOT_SUPPORTED;
 }
 
 static unsigned long psci_0_2_handler(u64 func_id, struct kvm_cpu_context *host_ctxt)
@@ -322,20 +280,23 @@ static unsigned long psci_1_0_handler(u64 func_id, struct kvm_cpu_context *host_
 
 bool kvm_host_psci_handler(struct kvm_cpu_context *host_ctxt)
 {
-	u64 func_id = get_psci_func_id(host_ctxt);
+	DECLARE_REG(u64, func_id, host_ctxt, 0);
 	unsigned long ret;
 
-	if (!is_psci_call(func_id))
-		return false;
-
 	switch (kvm_host_psci_config.version) {
 	case PSCI_VERSION(0, 1):
+		if (!is_psci_0_1_call(func_id))
+			return false;
 		ret = psci_0_1_handler(func_id, host_ctxt);
 		break;
 	case PSCI_VERSION(0, 2):
+		if (!is_psci_0_2_call(func_id))
+			return false;
 		ret = psci_0_2_handler(func_id, host_ctxt);
 		break;
 	default:
+		if (!is_psci_0_2_call(func_id))
+			return false;
 		ret = psci_1_0_handler(func_id, host_ctxt);
 		break;
 	}
-- 
2.29.2

[PATCH 09/18] KVM: Documentation: Add arm64 KVM_RUN error codes

[Marc Zyngier]

From: Alexandru Elisei <alexandru.elisei@arm.com>

The API documentation states that general error codes are not detailed, but
errors with specific meanings are. On arm64, KVM_RUN can return error
numbers with a different meaning than what is described by POSIX or the C99
standard (as taken from man 3 errno).

Absent from the newly documented error codes is ERANGE which can be
returned when making a change to the EL2 stage 1 tables if the address is
larger than the largest supported input address. Assuming no bugs in the
implementation, that is not possible because the input addresses which are
mapped are the result of applying the macro kern_hyp_va() on kernel virtual
addresses.

CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201201150157.223625-2-alexandru.elisei@arm.com
---
 Documentation/virt/kvm/api.rst | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index e00a66d72372..4e5316ed10e9 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -380,9 +380,14 @@ This ioctl is obsolete and has been removed.
 
 Errors:
 
-  =====      =============================
+  =======    ==============================================================
   EINTR      an unmasked signal is pending
-  =====      =============================
+  ENOEXEC    the vcpu hasn't been initialized or the guest tried to execute
+             instructions from device memory (arm64)
+  ENOSYS     data abort outside memslots with no syndrome info and
+             KVM_CAP_ARM_NISV_TO_USER not enabled (arm64)
+  EPERM      SVE feature set but not finalized (arm64)
+  =======    ==============================================================
 
 This ioctl is used to run a guest virtual cpu.  While there are no
 explicit parameters, there is an implicit parameter block that can be
-- 
2.29.2

[PATCH 10/18] KVM: arm64: arch_timer: Remove VGIC initialization check

[Marc Zyngier]

From: Alexandru Elisei <alexandru.elisei@arm.com>

kvm_timer_enable() is called in kvm_vcpu_first_run_init() after
kvm_vgic_map_resources() if the VGIC wasn't ready. kvm_vgic_map_resources()
is the only place where kvm->arch.vgic.ready is set to true.

For a v2 VGIC, kvm_vgic_map_resources() will attempt to initialize the VGIC
and set the initialized flag.

For a v3 VGIC, kvm_vgic_map_resources() will return an error code if the
VGIC isn't already initialized.

The end result is that if we've reached kvm_timer_enable(), the VGIC is
initialzed and ready and vgic_initialized() will always be true, so remove
this check.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
[maz: added comment about vgic initialisation, as suggested by Eric]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201201150157.223625-3-alexandru.elisei@arm.com
---
 arch/arm64/kvm/arch_timer.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 32ba6fbc3814..74e0699661e9 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -1129,9 +1129,10 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
 	if (!irqchip_in_kernel(vcpu->kvm))
 		goto no_vgic;
 
-	if (!vgic_initialized(vcpu->kvm))
-		return -ENODEV;
-
+	/*
+	 * At this stage, we have the guarantee that the vgic is both
+	 * available and initialized.
+	 */
 	if (!timer_irqs_are_valid(vcpu)) {
 		kvm_debug("incorrectly configured timer irqs\n");
 		return -EINVAL;
-- 
2.29.2

[PATCH 11/18] KVM: arm64: Move double-checked lock to kvm_vgic_map_resources()

[Marc Zyngier]

From: Alexandru Elisei <alexandru.elisei@arm.com>

kvm_vgic_map_resources() is called when a VCPU if first run and it maps all
the VGIC MMIO regions. To prevent double-initialization, the VGIC uses the
ready variable to keep track of the state of resources and the global KVM
mutex to protect against concurrent accesses. After the lock is taken, the
variable is checked again in case another VCPU took the lock between the
current VCPU reading ready equals false and taking the lock.

The double-checked lock pattern is spread across four different functions:
in kvm_vcpu_first_run_init(), in kvm_vgic_map_resource() and in
vgic_{v2,v3}_map_resources(), which makes it hard to reason about and
introduces minor code duplication. Consolidate the checks in
kvm_vgic_map_resources(), where the lock is taken.

No functional change intended.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201201150157.223625-4-alexandru.elisei@arm.com
---
 arch/arm64/kvm/arm.c            | 8 +++-----
 arch/arm64/kvm/vgic/vgic-init.c | 6 ++++++
 arch/arm64/kvm/vgic/vgic-v2.c   | 3 ---
 arch/arm64/kvm/vgic/vgic-v3.c   | 3 ---
 4 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e207e4541f55..ab782c480e9a 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -580,11 +580,9 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)
 		 * Map the VGIC hardware resources before running a vcpu the
 		 * first time on this VM.
 		 */
-		if (unlikely(!vgic_ready(kvm))) {
-			ret = kvm_vgic_map_resources(kvm);
-			if (ret)
-				return ret;
-		}
+		ret = kvm_vgic_map_resources(kvm);
+		if (ret)
+			return ret;
 	} else {
 		/*
 		 * Tell the rest of the code that there are userspace irqchip
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 32e32d67a127..a2f4d1c85f00 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -428,7 +428,13 @@ int kvm_vgic_map_resources(struct kvm *kvm)
 	struct vgic_dist *dist = &kvm->arch.vgic;
 	int ret = 0;
 
+	if (likely(vgic_ready(kvm)))
+		return 0;
+
 	mutex_lock(&kvm->lock);
+	if (vgic_ready(kvm))
+		goto out;
+
 	if (!irqchip_in_kernel(kvm))
 		goto out;
 
diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c
index ebf53a4e1296..7f38c1a93639 100644
--- a/arch/arm64/kvm/vgic/vgic-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-v2.c
@@ -306,9 +306,6 @@ int vgic_v2_map_resources(struct kvm *kvm)
 	struct vgic_dist *dist = &kvm->arch.vgic;
 	int ret = 0;
 
-	if (vgic_ready(kvm))
-		goto out;
-
 	if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) ||
 	    IS_VGIC_ADDR_UNDEF(dist->vgic_cpu_base)) {
 		kvm_err("Need to set vgic cpu and dist addresses first\n");
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 9cdf39a94a63..35029c5cb0f1 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -500,9 +500,6 @@ int vgic_v3_map_resources(struct kvm *kvm)
 	int ret = 0;
 	int c;
 
-	if (vgic_ready(kvm))
-		goto out;
-
 	kvm_for_each_vcpu(c, vcpu, kvm) {
 		struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 
-- 
2.29.2

[PATCH 12/18] KVM: arm64: Update comment in kvm_vgic_map_resources()

[Marc Zyngier]

From: Alexandru Elisei <alexandru.elisei@arm.com>

vgic_v3_map_resources() returns -EBUSY if the VGIC isn't initialized,
update the comment to kvm_vgic_map_resources() to match what the function
does.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201201150157.223625-5-alexandru.elisei@arm.com
---
 arch/arm64/kvm/vgic/vgic-init.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index a2f4d1c85f00..5b54787a9ad5 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -419,7 +419,8 @@ int vgic_lazy_init(struct kvm *kvm)
  * Map the MMIO regions depending on the VGIC model exposed to the guest
  * called on the first VCPU run.
  * Also map the virtual CPU interface into the VM.
- * v2/v3 derivatives call vgic_init if not already done.
+ * v2 calls vgic_init() if not already done.
+ * v3 and derivatives return an error if the VGIC is not initialized.
  * vgic_ready() returns true if this function has succeeded.
  * @kvm: kvm struct pointer
  */
-- 
2.29.2

[PATCH 13/18] KVM: arm64: Remove redundant call to kvm_pmu_vcpu_reset()

[Marc Zyngier]

From: Alexandru Elisei <alexandru.elisei@arm.com>

KVM_ARM_VCPU_INIT ioctl calls kvm_reset_vcpu(), which in turn resets the
PMU with a call to kvm_pmu_vcpu_reset(). The function zeroes the PMU
chained counters bitmap and stops all the counters with a perf event
attached. Because it is called before the VCPU has had the chance to run,
no perf events are in use and none are released.

kvm_arm_pmu_v3_enable(), called by kvm_vcpu_first_run_init() only if the
VCPU has been initialized, also resets the PMU. kvm_pmu_vcpu_reset() in
this case does the exact same thing as the previous call, so remove it.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201201150157.223625-6-alexandru.elisei@arm.com
---
 arch/arm64/kvm/pmu-emul.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 398f6df1bbe4..4ad66a532e38 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -850,8 +850,6 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
 		   return -EINVAL;
 	}
 
-	kvm_pmu_vcpu_reset(vcpu);
-
 	return 0;
 }
 
-- 
2.29.2

[PATCH 14/18] KVM: arm64: Consolidate dist->ready setting into kvm_vgic_map_resources()

[Marc Zyngier]

dist->ready setting is pointlessly spread across the two vgic
backends, while it could be consolidated in kvm_vgic_map_resources().

Move it there, and slightly simplify the flows in both backends.

Suggested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-init.c |  2 ++
 arch/arm64/kvm/vgic/vgic-v2.c   | 17 ++++++-----------
 arch/arm64/kvm/vgic/vgic-v3.c   | 18 ++++++------------
 3 files changed, 14 insertions(+), 23 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 5b54787a9ad5..052917deb149 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -446,6 +446,8 @@ int kvm_vgic_map_resources(struct kvm *kvm)
 
 	if (ret)
 		__kvm_vgic_destroy(kvm);
+	else
+		dist->ready = true;
 
 out:
 	mutex_unlock(&kvm->lock);
diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c
index 7f38c1a93639..11934c2af2f4 100644
--- a/arch/arm64/kvm/vgic/vgic-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-v2.c
@@ -309,14 +309,12 @@ int vgic_v2_map_resources(struct kvm *kvm)
 	if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) ||
 	    IS_VGIC_ADDR_UNDEF(dist->vgic_cpu_base)) {
 		kvm_err("Need to set vgic cpu and dist addresses first\n");
-		ret = -ENXIO;
-		goto out;
+		return -ENXIO;
 	}
 
 	if (!vgic_v2_check_base(dist->vgic_dist_base, dist->vgic_cpu_base)) {
 		kvm_err("VGIC CPU and dist frames overlap\n");
-		ret = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 
 	/*
@@ -326,13 +324,13 @@ int vgic_v2_map_resources(struct kvm *kvm)
 	ret = vgic_init(kvm);
 	if (ret) {
 		kvm_err("Unable to initialize VGIC dynamic data structures\n");
-		goto out;
+		return ret;
 	}
 
 	ret = vgic_register_dist_iodev(kvm, dist->vgic_dist_base, VGIC_V2);
 	if (ret) {
 		kvm_err("Unable to register VGIC MMIO regions\n");
-		goto out;
+		return ret;
 	}
 
 	if (!static_branch_unlikely(&vgic_v2_cpuif_trap)) {
@@ -341,14 +339,11 @@ int vgic_v2_map_resources(struct kvm *kvm)
 					    KVM_VGIC_V2_CPU_SIZE, true);
 		if (ret) {
 			kvm_err("Unable to remap VGIC CPU to VCPU\n");
-			goto out;
+			return ret;
 		}
 	}
 
-	dist->ready = true;
-
-out:
-	return ret;
+	return 0;
 }
 
 DEFINE_STATIC_KEY_FALSE(vgic_v2_cpuif_trap);
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 35029c5cb0f1..52915b342351 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -505,21 +505,18 @@ int vgic_v3_map_resources(struct kvm *kvm)
 
 		if (IS_VGIC_ADDR_UNDEF(vgic_cpu->rd_iodev.base_addr)) {
 			kvm_debug("vcpu %d redistributor base not set\n", c);
-			ret = -ENXIO;
-			goto out;
+			return -ENXIO;
 		}
 	}
 
 	if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base)) {
 		kvm_err("Need to set vgic distributor addresses first\n");
-		ret = -ENXIO;
-		goto out;
+		return -ENXIO;
 	}
 
 	if (!vgic_v3_check_base(kvm)) {
 		kvm_err("VGIC redist and dist frames overlap\n");
-		ret = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 
 	/*
@@ -527,22 +524,19 @@ int vgic_v3_map_resources(struct kvm *kvm)
 	 * the VGIC before we need to use it.
 	 */
 	if (!vgic_initialized(kvm)) {
-		ret = -EBUSY;
-		goto out;
+		return -EBUSY;
 	}
 
 	ret = vgic_register_dist_iodev(kvm, dist->vgic_dist_base, VGIC_V3);
 	if (ret) {
 		kvm_err("Unable to register VGICv3 dist MMIO regions\n");
-		goto out;
+		return ret;
 	}
 
 	if (kvm_vgic_global_state.has_gicv4_1)
 		vgic_v4_configure_vsgis(kvm);
-	dist->ready = true;
 
-out:
-	return ret;
+	return 0;
 }
 
 DEFINE_STATIC_KEY_FALSE(vgic_v3_cpuif_trap);
-- 
2.29.2

[PATCH 15/18] KVM: arm64: Fix hyp_cpu_pm_{init,exit} __init annotation

[Marc Zyngier]

The __init annotations on hyp_cpu_pm_{init,exit} are obviously incorrect,
and the build system shouts at you if you enable DEBUG_SECTION_MISMATCH.

Nothing really bad happens as we never execute that code outside of the
init context, but we can't label the callers as __int either, as kvm_init
isn't __init itself. Oh well.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20201223120854.255347-1-maz@kernel.org
---
 arch/arm64/kvm/arm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index ab782c480e9a..04c44853b103 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1568,12 +1568,12 @@ static struct notifier_block hyp_init_cpu_pm_nb = {
 	.notifier_call = hyp_init_cpu_pm_notifier,
 };
 
-static void __init hyp_cpu_pm_init(void)
+static void hyp_cpu_pm_init(void)
 {
 	if (!is_protected_kvm_enabled())
 		cpu_pm_register_notifier(&hyp_init_cpu_pm_nb);
 }
-static void __init hyp_cpu_pm_exit(void)
+static void hyp_cpu_pm_exit(void)
 {
 	if (!is_protected_kvm_enabled())
 		cpu_pm_unregister_notifier(&hyp_init_cpu_pm_nb);
-- 
2.29.2

[PATCH 16/18] KVM: arm64: Remove spurious semicolon in reg_to_encoding()

[Marc Zyngier]

Although not a problem right now, it flared up while working
on some other aspects of the code-base. Remove the useless
semicolon.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index d46e7f706cb0..42ccc27fb684 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -923,7 +923,7 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 
 #define reg_to_encoding(x)						\
 	sys_reg((u32)(x)->Op0, (u32)(x)->Op1,				\
-		(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2);
+		(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2)
 
 /* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
 #define DBG_BCR_BVR_WCR_WVR_EL1(n)					\
-- 
2.29.2

[PATCH 17/18] KVM: arm64: Replace KVM_ARM_PMU with HW_PERF_EVENTS

[Marc Zyngier]

KVM_ARM_PMU only existed for the benefit of 32bit ARM hosts,
and makes no sense now that we are 64bit only. Get rid of it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/Kconfig  | 8 --------
 arch/arm64/kvm/Makefile | 2 +-
 include/kvm/arm_pmu.h   | 2 +-
 3 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 043756db8f6e..3964acf5451e 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -49,14 +49,6 @@ if KVM
 
 source "virt/kvm/Kconfig"
 
-config KVM_ARM_PMU
-	bool "Virtual Performance Monitoring Unit (PMU) support"
-	depends on HW_PERF_EVENTS
-	default y
-	help
-	  Adds support for a virtual Performance Monitoring Unit (PMU) in
-	  virtual machines.
-
 endif # KVM
 
 endif # VIRTUALIZATION
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 60fd181df624..13b017284bf9 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -24,4 +24,4 @@ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \
 	 vgic/vgic-mmio-v3.o vgic/vgic-kvm-device.o \
 	 vgic/vgic-its.o vgic/vgic-debug.o
 
-kvm-$(CONFIG_KVM_ARM_PMU)  += pmu-emul.o
+kvm-$(CONFIG_HW_PERF_EVENTS)  += pmu-emul.o
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index fc85f50fa0e9..8dcb3e1477bc 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -13,7 +13,7 @@
 #define ARMV8_PMU_CYCLE_IDX		(ARMV8_PMU_MAX_COUNTERS - 1)
 #define ARMV8_PMU_MAX_COUNTER_PAIRS	((ARMV8_PMU_MAX_COUNTERS + 1) >> 1)
 
-#ifdef CONFIG_KVM_ARM_PMU
+#ifdef CONFIG_HW_PERF_EVENTS
 
 struct kvm_pmc {
 	u8 idx;	/* index into the pmu->pmc array */
-- 
2.29.2

[PATCH 18/18] arm64: cpufeature: remove non-exist CONFIG_KVM_ARM_HOST

[Marc Zyngier]

From: Shannon Zhao <shannon.zhao@linux.alibaba.com>

Commit d82755b2e781 ("KVM: arm64: Kill off CONFIG_KVM_ARM_HOST") deletes
CONFIG_KVM_ARM_HOST option, it should use CONFIG_KVM instead.

Just remove CONFIG_KVM_ARM_HOST here.

Fixes: d82755b2e781 ("KVM: arm64: Kill off CONFIG_KVM_ARM_HOST")
Signed-off-by: Shannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1609760324-92271-1-git-send-email-shannon.zhao@linux.alibaba.com
---
 arch/arm64/kernel/cpufeature.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index d96f4554282d..bc3549663957 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2558,7 +2558,7 @@ static void verify_hyp_capabilities(void)
 	int parange, ipa_max;
 	unsigned int safe_vmid_bits, vmid_bits;
 
-	if (!IS_ENABLED(CONFIG_KVM) || !IS_ENABLED(CONFIG_KVM_ARM_HOST))
+	if (!IS_ENABLED(CONFIG_KVM))
 		return;
 
 	safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
-- 
2.29.2

Re: [GIT PULL] KVM/arm64 fixes for 5.11, take #1

[Paolo Bonzini]

On 07/01/21 12:20, Marc Zyngier wrote:
>    git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git tags/kvmarm-fixes-5.11-1

Pulled, thanks.

Paolo

Re: [GIT PULL] KVM/arm64 fixes for 5.11, take #1

[Paolo Bonzini]

On 07/01/21 12:20, Marc Zyngier wrote:
>    git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git tags/kvmarm-fixes-5.11-1

Looks like there are issues with the upstream changes brought in by this 
pull request.  Unless my bisection is quick tomorrow it may not make it 
into 5.11-rc3.  In any case, it's in my hands.

Paolo

Re: [GIT PULL] KVM/arm64 fixes for 5.11, take #1

[Marc Zyngier]

Hi Paolo,

On 2021-01-07 23:09, Paolo Bonzini wrote:
> On 07/01/21 12:20, Marc Zyngier wrote:
>>    git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git 
>> tags/kvmarm-fixes-5.11-1
> 
> Looks like there are issues with the upstream changes brought in by
> this pull request.  Unless my bisection is quick tomorrow it may not
> make it into 5.11-rc3.  In any case, it's in my hands.

I'm not sure what you mean by "upstream changes", as there is no
additional changes on top of what is describe in this pull request,
which is directly based on the tag  you pulled for the merge window.

If there is an issue with any of these 18 patches themselves, please
shout as soon as you can.

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...

Re: [GIT PULL] KVM/arm64 fixes for 5.11, take #1

[Paolo Bonzini]

On 08/01/21 09:22, Marc Zyngier wrote:
>>
>>>    git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git 
>>> tags/kvmarm-fixes-5.11-1
>>
>> Looks like there are issues with the upstream changes brought in by
>> this pull request.  Unless my bisection is quick tomorrow it may not
>> make it into 5.11-rc3.  In any case, it's in my hands.
> 
> I'm not sure what you mean by "upstream changes", as there is no
> additional changes on top of what is describe in this pull request,
> which is directly based on the tag  you pulled for the merge window.
> 
> If there is an issue with any of these 18 patches themselves, please
> shout as soon as you can.

You're right, it's not related to this pull request but just to Linus's 
tree.  It was too late yesterday, and now it's all set for sending it out.

Paolo