[PATCH v7 0/5] KVM: arm64: Errata management for VM Live migration

[PATCH v7 0/5] KVM: arm64: Errata management for VM Live migration

[Shameer Kolothum]

Hi,

v6-->v7
https://lore.kernel.org/kvmarm/20250205132222.55816-1-shameerali.kolothum.thodi@huawei.com/

Changes:
 -Introduced KVM_REG_ARM_VENDOR_HYP_BMAP_2 register for new hypercall
  support(patch #3)
 -Added selftest for KVM_REG_ARM_VENDOR_HYP_BMAP_2(patch #5).

This can be sanity tested by the Qemu branch here,
https://github.com/hisilicon/qemu/tree/v9.0-nv-rfcv4-vcpu-model-v2-target-cpu-errata
(branch based on Eric's/Connie's NV + custom CPU series)
Eg: to specify target impl CPUs,
-machine virt,.., x-target-impl-cpus=0xMIDR1:0xREVIDR1-0xMIDR2:REVIDR2

Please take a look and let me know your feedback.

Thanks,
Shameer

v5 --> v6
https://lore.kernel.org/kvmarm/20250124151732.6072-1-shameerali.kolothum.thodi@huawei.com/

-Addressed comments from Oliver,
 -Changed version to 32 bit to match SMCCC_VERSION
 -Don't advertise pKVM hypercalls to guests.
 -Moved hypercall invocation to kvm_guest.c
v4 --> v5
https://lore.kernel.org/kvmarm/20241218105345.73472-1-shameerali.kolothum.thodi@huawei.com/

-Addressed comments from Marc,
 -Added an hypercall to retrieve version and number of supported target
  impl CPUs.
 -Added a check for KVM hypercall services availability.
-Removed R-by tags from Connie & Sebastian as patches 2 & 4 are now
 changed a bit. Please take another look.

v3 --> v4(Minor updates)
https://lore.kernel.org/kvmarm/20241209115311.40496-1-shameerali.kolothum.thodi@huawei.com/

 -Changed MIDR/REVIDR to 64 bits based on feedback from Connie
  and Marc(Patch #3).
 -Added R-by tags from Sebastian (Thanks!).

RFC v2 --> v3
https://lore.kernel.org/kvmarm/20241024094012.29452-1-shameerali.kolothum.thodi@huawei.com/

 -Addressed comments from Oliver(Thanks!).
 -Using implementation CPUs MIDR/REVIDR when it is set for
  _midr_range() functions(Patch 1 & 3)
 -New hypercall for retrieving implementation CPUs(Patch #2).
 -Dropped RFC.

RFC v1 --> RFCv2:
https://lore.kernel.org/kvmarm/20241011075053.80540-1-shameerali.kolothum.thodi@huawei.com/
 -Introduced hypercalls to retrieve target CPUs info from user space VMM.
  see patch #1 for details.
 -Patch #2 uses the hypercall to retrieve the target CPU info if any.
 -Use the target CPUs MIDR/REVIDR in errata enablement. See patch #3.

Background from v1:

On ARM64 platforms most of the errata workarounds are based on CPU
MIDR/REVIDR values and a number of these workarounds need to be
implemented by the Guest kernel as well. This creates a problem when
Guest needs to be migrated to a platform that differs in these
MIDR/REVIDR values even if the VMM can come up with a common minimum
feature list for the Guest using the recently introduced "Writable
ID registers" support.

(This is roughly based on a discussion I had with Marc and Oliver
at KVM forum. Marc outlined his idea for a solution and this is an
attempt to implement it. Thanks to both and I take all the blame
if this is nowhere near what is intended/required)

Shameer Kolothum (5):
  arm64: Modify _midr_range() functions to read MIDR/REVIDR internally
  KVM: arm64: Introduce hypercall support for retrieving target
    implementations
  KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2
  smccc/kvm_guest: Enable errata based on implementation CPUs
  KVM: selftests: Add test for KVM_REG_ARM_VENDOR_HYP_BMAP_2

 .../virt/kvm/arm/fw-pseudo-registers.rst      | 15 ++++-
 Documentation/virt/kvm/arm/hypercalls.rst     | 59 +++++++++++++++++
 arch/arm64/include/asm/cputype.h              | 50 ++++++++++-----
 arch/arm64/include/asm/hypervisor.h           |  1 +
 arch/arm64/include/asm/kvm_host.h             |  3 +-
 arch/arm64/include/asm/mmu.h                  |  3 +-
 arch/arm64/include/uapi/asm/kvm.h             | 12 ++++
 arch/arm64/kernel/cpu_errata.c                | 37 ++++++++---
 arch/arm64/kernel/cpufeature.c                |  8 ++-
 arch/arm64/kernel/image-vars.h                |  2 +
 arch/arm64/kernel/proton-pack.c               | 17 +++--
 arch/arm64/kvm/hypercalls.c                   | 13 ++++
 arch/arm64/kvm/vgic/vgic-v3.c                 |  2 +-
 drivers/clocksource/arm_arch_timer.c          |  2 +-
 drivers/firmware/smccc/kvm_guest.c            | 63 +++++++++++++++++++
 include/linux/arm-smccc.h                     | 15 +++++
 tools/arch/arm64/include/uapi/asm/kvm.h       | 12 ++++
 .../selftests/kvm/arm64/get-reg-list.c        |  1 +
 .../testing/selftests/kvm/arm64/hypercalls.c  | 46 +++++++++++---
 19 files changed, 308 insertions(+), 53 deletions(-)

-- 
2.47.0

[PATCH v7 1/5] arm64: Modify _midr_range() functions to read MIDR/REVIDR internally

[Shameer Kolothum]

These changes lay the groundwork for adding support for guest kernels,
allowing them to leverage target CPU implementations provided by the
VMM.

No functional changes intended.

Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 arch/arm64/include/asm/cputype.h     | 28 ++++++++++++++--------------
 arch/arm64/include/asm/mmu.h         |  3 +--
 arch/arm64/kernel/cpu_errata.c       | 23 +++++++++++++----------
 arch/arm64/kernel/cpufeature.c       |  6 +++---
 arch/arm64/kernel/proton-pack.c      | 17 ++++++++---------
 arch/arm64/kvm/vgic/vgic-v3.c        |  2 +-
 drivers/clocksource/arm_arch_timer.c |  2 +-
 7 files changed, 41 insertions(+), 40 deletions(-)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 6f3f4142e214..2a76f0e30006 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -231,6 +231,16 @@
 
 #define read_cpuid(reg)			read_sysreg_s(SYS_ ## reg)
 
+/*
+ * The CPU ID never changes at run time, so we might as well tell the
+ * compiler that it's constant.  Use this function to read the CPU ID
+ * rather than directly reading processor_id or read_cpuid() directly.
+ */
+static inline u32 __attribute_const__ read_cpuid_id(void)
+{
+	return read_cpuid(MIDR_EL1);
+}
+
 /*
  * Represent a range of MIDR values for a given CPU model and a
  * range of variant/revision values.
@@ -266,31 +276,21 @@ static inline bool midr_is_cpu_model_range(u32 midr, u32 model, u32 rv_min,
 	return _model == model && rv >= rv_min && rv <= rv_max;
 }
 
-static inline bool is_midr_in_range(u32 midr, struct midr_range const *range)
+static inline bool is_midr_in_range(struct midr_range const *range)
 {
-	return midr_is_cpu_model_range(midr, range->model,
+	return midr_is_cpu_model_range(read_cpuid_id(), range->model,
 				       range->rv_min, range->rv_max);
 }
 
 static inline bool
-is_midr_in_range_list(u32 midr, struct midr_range const *ranges)
+is_midr_in_range_list(struct midr_range const *ranges)
 {
 	while (ranges->model)
-		if (is_midr_in_range(midr, ranges++))
+		if (is_midr_in_range(ranges++))
 			return true;
 	return false;
 }
 
-/*
- * The CPU ID never changes at run time, so we might as well tell the
- * compiler that it's constant.  Use this function to read the CPU ID
- * rather than directly reading processor_id or read_cpuid() directly.
- */
-static inline u32 __attribute_const__ read_cpuid_id(void)
-{
-	return read_cpuid(MIDR_EL1);
-}
-
 static inline u64 __attribute_const__ read_cpuid_mpidr(void)
 {
 	return read_cpuid(MPIDR_EL1);
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index 662471cfc536..30a29e88994b 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -101,8 +101,7 @@ static inline bool kaslr_requires_kpti(void)
 	if (IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
 		extern const struct midr_range cavium_erratum_27456_cpus[];
 
-		if (is_midr_in_range_list(read_cpuid_id(),
-					  cavium_erratum_27456_cpus))
+		if (is_midr_in_range_list(cavium_erratum_27456_cpus))
 			return false;
 	}
 
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 7ce555862895..99b55893fc4e 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -15,30 +15,34 @@
 #include <asm/smp_plat.h>
 
 static bool __maybe_unused
-is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
+__is_affected_midr_range(const struct arm64_cpu_capabilities *entry,
+			 u32 midr, u32 revidr)
 {
 	const struct arm64_midr_revidr *fix;
-	u32 midr = read_cpuid_id(), revidr;
-
-	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
-	if (!is_midr_in_range(midr, &entry->midr_range))
+	if (!is_midr_in_range(&entry->midr_range))
 		return false;
 
 	midr &= MIDR_REVISION_MASK | MIDR_VARIANT_MASK;
-	revidr = read_cpuid(REVIDR_EL1);
 	for (fix = entry->fixed_revs; fix && fix->revidr_mask; fix++)
 		if (midr == fix->midr_rv && (revidr & fix->revidr_mask))
 			return false;
-
 	return true;
 }
 
+static bool __maybe_unused
+is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
+{
+	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
+	return __is_affected_midr_range(entry, read_cpuid_id(),
+					read_cpuid(REVIDR_EL1));
+}
+
 static bool __maybe_unused
 is_affected_midr_range_list(const struct arm64_cpu_capabilities *entry,
 			    int scope)
 {
 	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
-	return is_midr_in_range_list(read_cpuid_id(), entry->midr_range_list);
+	return is_midr_in_range_list(entry->midr_range_list);
 }
 
 static bool __maybe_unused
@@ -186,12 +190,11 @@ static bool __maybe_unused
 has_neoverse_n1_erratum_1542419(const struct arm64_cpu_capabilities *entry,
 				int scope)
 {
-	u32 midr = read_cpuid_id();
 	bool has_dic = read_cpuid_cachetype() & BIT(CTR_EL0_DIC_SHIFT);
 	const struct midr_range range = MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1);
 
 	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
-	return is_midr_in_range(midr, &range) && has_dic;
+	return is_midr_in_range(&range) && has_dic;
 }
 
 #ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 4eb7c6698ae4..72e876f37cd4 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1792,7 +1792,7 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
 	char const *str = "kpti command line option";
 	bool meltdown_safe;
 
-	meltdown_safe = is_midr_in_range_list(read_cpuid_id(), kpti_safe_list);
+	meltdown_safe = is_midr_in_range_list(kpti_safe_list);
 
 	/* Defer to CPU feature registers */
 	if (has_cpuid_feature(entry, scope))
@@ -1862,7 +1862,7 @@ static bool has_nv1(const struct arm64_cpu_capabilities *entry, int scope)
 
 	return (__system_matches_cap(ARM64_HAS_NESTED_VIRT) &&
 		!(has_cpuid_feature(entry, scope) ||
-		  is_midr_in_range_list(read_cpuid_id(), nv1_ni_list)));
+		  is_midr_in_range_list(nv1_ni_list)));
 }
 
 #if defined(ID_AA64MMFR0_EL1_TGRAN_LPA2) && defined(ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_LPA2)
@@ -2045,7 +2045,7 @@ static bool cpu_has_broken_dbm(void)
 		{},
 	};
 
-	return is_midr_in_range_list(read_cpuid_id(), cpus);
+	return is_midr_in_range_list(cpus);
 }
 
 static bool cpu_can_use_dbm(const struct arm64_cpu_capabilities *cap)
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index da53722f95d4..a573fa40d4b6 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -172,7 +172,7 @@ static enum mitigation_state spectre_v2_get_cpu_hw_mitigation_state(void)
 		return SPECTRE_UNAFFECTED;
 
 	/* Alternatively, we have a list of unaffected CPUs */
-	if (is_midr_in_range_list(read_cpuid_id(), spectre_v2_safe_list))
+	if (is_midr_in_range_list(spectre_v2_safe_list))
 		return SPECTRE_UNAFFECTED;
 
 	return SPECTRE_VULNERABLE;
@@ -331,7 +331,7 @@ bool has_spectre_v3a(const struct arm64_cpu_capabilities *entry, int scope)
 	};
 
 	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
-	return is_midr_in_range_list(read_cpuid_id(), spectre_v3a_unsafe_list);
+	return is_midr_in_range_list(spectre_v3a_unsafe_list);
 }
 
 void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused)
@@ -475,7 +475,7 @@ static enum mitigation_state spectre_v4_get_cpu_hw_mitigation_state(void)
 		{ /* sentinel */ },
 	};
 
-	if (is_midr_in_range_list(read_cpuid_id(), spectre_v4_safe_list))
+	if (is_midr_in_range_list(spectre_v4_safe_list))
 		return SPECTRE_UNAFFECTED;
 
 	/* CPU features are detected first */
@@ -878,13 +878,13 @@ u8 spectre_bhb_loop_affected(int scope)
 			{},
 		};
 
-		if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k32_list))
+		if (is_midr_in_range_list(spectre_bhb_k32_list))
 			k = 32;
-		else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k24_list))
+		else if (is_midr_in_range_list(spectre_bhb_k24_list))
 			k = 24;
-		else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k11_list))
+		else if (is_midr_in_range_list(spectre_bhb_k11_list))
 			k = 11;
-		else if (is_midr_in_range_list(read_cpuid_id(), spectre_bhb_k8_list))
+		else if (is_midr_in_range_list(spectre_bhb_k8_list))
 			k =  8;
 
 		max_bhb_k = max(max_bhb_k, k);
@@ -926,8 +926,7 @@ static bool is_spectre_bhb_fw_affected(int scope)
 		MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
 		{},
 	};
-	bool cpu_in_list = is_midr_in_range_list(read_cpuid_id(),
-					 spectre_bhb_firmware_mitigated_list);
+	bool cpu_in_list = is_midr_in_range_list(spectre_bhb_firmware_mitigated_list);
 
 	if (scope != SCOPE_LOCAL_CPU)
 		return system_affected;
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index d7233ab982d0..87a8a96c7a41 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -633,7 +633,7 @@ static const struct midr_range broken_seis[] = {
 static bool vgic_v3_broken_seis(void)
 {
 	return ((kvm_vgic_global_state.ich_vtr_el2 & ICH_VTR_SEIS_MASK) &&
-		is_midr_in_range_list(read_cpuid_id(), broken_seis));
+		is_midr_in_range_list(broken_seis));
 }
 
 /**
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 808f259781fd..981a578043a5 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -842,7 +842,7 @@ static u64 __arch_timer_check_delta(void)
 		{},
 	};
 
-	if (is_midr_in_range_list(read_cpuid_id(), broken_cval_midrs)) {
+	if (is_midr_in_range_list(broken_cval_midrs)) {
 		pr_warn_once("Broken CNTx_CVAL_EL1, using 31 bit TVAL instead.\n");
 		return CLOCKSOURCE_MASK(31);
 	}
-- 
2.47.0

[PATCH v7 2/5] KVM: arm64: Introduce hypercall support for retrieving target implementations

[Shameer Kolothum]

If the Guest requires migration to multiple targets, these hypercalls
will provide a way to retrieve the target CPU implementations from
the user space VMM.

Subsequent patch will use this to enable the associated errata.

Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Suggested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 Documentation/virt/kvm/arm/hypercalls.rst | 59 +++++++++++++++++++++++
 include/linux/arm-smccc.h                 | 15 ++++++
 2 files changed, 74 insertions(+)

diff --git a/Documentation/virt/kvm/arm/hypercalls.rst b/Documentation/virt/kvm/arm/hypercalls.rst
index af7bc2c2e0cb..7400a89aabf8 100644
--- a/Documentation/virt/kvm/arm/hypercalls.rst
+++ b/Documentation/virt/kvm/arm/hypercalls.rst
@@ -142,3 +142,62 @@ region is equal to the memory protection granule advertised by
 |                     |          |    +---------------------------------------------+
 |                     |          |    | ``INVALID_PARAMETER (-3)``                  |
 +---------------------+----------+----+---------------------------------------------+
+
+``ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_VER_FUNC_ID``
+-------------------------------------------------------
+Request the target CPU implementation version information and the number of target
+implementations for the Guest VM.
+
++---------------------+-------------------------------------------------------------+
+| Presence:           | Optional;  KVM/ARM64 Guests only                            |
++---------------------+-------------------------------------------------------------+
+| Calling convention: | HVC64                                                       |
++---------------------+----------+--------------------------------------------------+
+| Function ID:        | (uint32) | 0xC6000040                                       |
++---------------------+----------+--------------------------------------------------+
+| Arguments:          | None                                                        |
++---------------------+----------+----+---------------------------------------------+
+| Return Values:      | (int64)  | R0 | ``SUCCESS (0)``                             |
+|                     |          |    +---------------------------------------------+
+|                     |          |    | ``NOT_SUPPORTED (-1)``                      |
+|                     +----------+----+---------------------------------------------+
+|                     | (uint64) | R1 | Bits [63:32] Reserved/Must be zero          |
+|                     |          |    +---------------------------------------------+
+|                     |          |    | Bits [31:16] Major version                  |
+|                     |          |    +---------------------------------------------+
+|                     |          |    | Bits [15:0] Minor version                   |
+|                     +----------+----+---------------------------------------------+
+|                     | (uint64) | R2 | Number of target implementations            |
+|                     +----------+----+---------------------------------------------+
+|                     | (uint64) | R3 | Reserved / Must be zero                     |
++---------------------+----------+----+---------------------------------------------+
+
+``ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID``
+-------------------------------------------------------
+
+Request the target CPU implementation information for the Guest VM. The Guest kernel
+will use this information to enable the associated errata.
+
++---------------------+-------------------------------------------------------------+
+| Presence:           | Optional;  KVM/ARM64 Guests only                            |
++---------------------+-------------------------------------------------------------+
+| Calling convention: | HVC64                                                       |
++---------------------+----------+--------------------------------------------------+
+| Function ID:        | (uint32) | 0xC6000041                                       |
++---------------------+----------+----+---------------------------------------------+
+| Arguments:          | (uint64) | R1 | selected implementation index               |
+|                     +----------+----+---------------------------------------------+
+|                     | (uint64) | R2 | Reserved / Must be zero                     |
+|                     +----------+----+---------------------------------------------+
+|                     | (uint64) | R3 | Reserved / Must be zero                     |
++---------------------+----------+----+---------------------------------------------+
+| Return Values:      | (int64)  | R0 | ``SUCCESS (0)``                             |
+|                     |          |    +---------------------------------------------+
+|                     |          |    | ``INVALID_PARAMETER (-3)``                  |
+|                     +----------+----+---------------------------------------------+
+|                     | (uint64) | R1 | MIDR_EL1 of the selected implementation     |
+|                     +----------+----+---------------------------------------------+
+|                     | (uint64) | R2 | REVIDR_EL1 of the selected implementation   |
+|                     +----------+----+---------------------------------------------+
+|                     | (uint64) | R3 | AIDR_EL1  of the selected implementation    |
++---------------------+----------+----+---------------------------------------------+
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 67f6fdf2e7cd..f19be5754090 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -179,6 +179,9 @@
 #define ARM_SMCCC_KVM_FUNC_PKVM_RESV_62		62
 #define ARM_SMCCC_KVM_FUNC_PKVM_RESV_63		63
 /* End of pKVM hypercall range */
+#define ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_VER	64
+#define ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_CPUS	65
+
 #define ARM_SMCCC_KVM_FUNC_FEATURES_2		127
 #define ARM_SMCCC_KVM_NUM_FUNCS			128
 
@@ -225,6 +228,18 @@
 			   ARM_SMCCC_OWNER_VENDOR_HYP,			\
 			   ARM_SMCCC_KVM_FUNC_MMIO_GUARD)
 
+#define ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_VER_FUNC_ID		\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
+			   ARM_SMCCC_SMC_64,				\
+			   ARM_SMCCC_OWNER_VENDOR_HYP,			\
+			   ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_VER)
+
+#define ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID		\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
+			   ARM_SMCCC_SMC_64,				\
+			   ARM_SMCCC_OWNER_VENDOR_HYP,			\
+			   ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_CPUS)
+
 /* ptp_kvm counter type ID */
 #define KVM_PTP_VIRT_COUNTER			0
 #define KVM_PTP_PHYS_COUNTER			1
-- 
2.47.0

[PATCH v7 3/5] KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2

[Shameer Kolothum]

The vendor_hyp_bmap bitmap holds the information about the Vendor Hyp
services available to the user space and can be get/set using
{G, S}ET_ONE_REG interfaces. This is done using the pseudo-firmware
bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP.

At present, this bitmap is a 64 bit one and since the function numbers
for newly added DISCOVER_IPML_* hypercalls are 64-65, introduce
another pseudo-firmware bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP_2.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 .../virt/kvm/arm/fw-pseudo-registers.rst          | 15 ++++++++++++++-
 arch/arm64/include/asm/kvm_host.h                 |  3 ++-
 arch/arm64/include/uapi/asm/kvm.h                 | 12 ++++++++++++
 arch/arm64/kvm/hypercalls.c                       | 13 +++++++++++++
 4 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/Documentation/virt/kvm/arm/fw-pseudo-registers.rst b/Documentation/virt/kvm/arm/fw-pseudo-registers.rst
index b90fd0b0fa66..d78b53b05dfc 100644
--- a/Documentation/virt/kvm/arm/fw-pseudo-registers.rst
+++ b/Documentation/virt/kvm/arm/fw-pseudo-registers.rst
@@ -116,7 +116,7 @@ The pseudo-firmware bitmap register are as follows:
       ARM DEN0057A.
 
 * KVM_REG_ARM_VENDOR_HYP_BMAP:
-    Controls the bitmap of the Vendor specific Hypervisor Service Calls.
+    Controls the bitmap of the Vendor specific Hypervisor Service Calls[0-63].
 
   The following bits are accepted:
 
@@ -127,6 +127,19 @@ The pseudo-firmware bitmap register are as follows:
     Bit-1: KVM_REG_ARM_VENDOR_HYP_BIT_PTP:
       The bit represents the Precision Time Protocol KVM service.
 
+* KVM_REG_ARM_VENDOR_HYP_BMAP_2:
+    Controls the bitmap of the Vendor specific Hypervisor Service Calls[64-127].
+
+  The following bits are accepted:
+
+    Bit-0: KVM_REG_ARM_VENDOR_HYP_BIT_DISCOVER_IMPL_VER
+      This represents the ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_VER_FUNC_ID
+      function-id. This is reset to 0.
+
+    Bit-1: KVM_REG_ARM_VENDOR_HYP_BIT_DISCOVER_IMPL_CPUS
+      This represents the ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID
+      function-id. This is reset to 0.
+
 Errors:
 
     =======  =============================================================
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 7cfa024de4e3..4cea172ebaaa 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -237,7 +237,8 @@ struct kvm_arch_memory_slot {
 struct kvm_smccc_features {
 	unsigned long std_bmap;
 	unsigned long std_hyp_bmap;
-	unsigned long vendor_hyp_bmap;
+	unsigned long vendor_hyp_bmap; /* Function numbers 0-63 */
+	unsigned long vendor_hyp_bmap_2; /* Function numbers 64-127 */
 };
 
 typedef unsigned int pkvm_handle_t;
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 568bf858f319..072feeff74d0 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -371,6 +371,7 @@ enum {
 #endif
 };
 
+/* Vendor hyper call function numbers 0-63 */
 #define KVM_REG_ARM_VENDOR_HYP_BMAP		KVM_REG_ARM_FW_FEAT_BMAP_REG(2)
 
 enum {
@@ -381,6 +382,17 @@ enum {
 #endif
 };
 
+/* Vendor hyper call function numbers 64-127 */
+#define KVM_REG_ARM_VENDOR_HYP_BMAP_2		KVM_REG_ARM_FW_FEAT_BMAP_REG(3)
+
+enum {
+	KVM_REG_ARM_VENDOR_HYP_BIT_DISCOVER_IMPL_VER	= 0,
+	KVM_REG_ARM_VENDOR_HYP_BIT_DISCOVER_IMPL_CPUS	= 1,
+#ifdef __KERNEL__
+	KVM_REG_ARM_VENDOR_HYP_BMAP_2_BIT_COUNT,
+#endif
+};
+
 /* Device Control API on vm fd */
 #define KVM_ARM_VM_SMCCC_CTRL		0
 #define   KVM_ARM_VM_SMCCC_FILTER	0
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
index 27ce4cb44904..569941eeb3fe 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -15,6 +15,8 @@
 	GENMASK(KVM_REG_ARM_STD_HYP_BMAP_BIT_COUNT - 1, 0)
 #define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES			\
 	GENMASK(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_COUNT - 1, 0)
+#define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES_2			\
+	GENMASK(KVM_REG_ARM_VENDOR_HYP_BMAP_2_BIT_COUNT - 1, 0)
 
 static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val)
 {
@@ -360,6 +362,8 @@ int kvm_smccc_call_handler(struct kvm_vcpu *vcpu)
 		break;
 	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
 		val[0] = smccc_feat->vendor_hyp_bmap;
+		/* Function numbers 2-63 are reserved for pKVM for now */
+		val[2] = smccc_feat->vendor_hyp_bmap_2;
 		break;
 	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
 		kvm_ptp_get_time(vcpu, val);
@@ -387,6 +391,7 @@ static const u64 kvm_arm_fw_reg_ids[] = {
 	KVM_REG_ARM_STD_BMAP,
 	KVM_REG_ARM_STD_HYP_BMAP,
 	KVM_REG_ARM_VENDOR_HYP_BMAP,
+	KVM_REG_ARM_VENDOR_HYP_BMAP_2,
 };
 
 void kvm_arm_init_hypercalls(struct kvm *kvm)
@@ -497,6 +502,9 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	case KVM_REG_ARM_VENDOR_HYP_BMAP:
 		val = READ_ONCE(smccc_feat->vendor_hyp_bmap);
 		break;
+	case KVM_REG_ARM_VENDOR_HYP_BMAP_2:
+		val = READ_ONCE(smccc_feat->vendor_hyp_bmap_2);
+		break;
 	default:
 		return -ENOENT;
 	}
@@ -527,6 +535,10 @@ static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val)
 		fw_reg_bmap = &smccc_feat->vendor_hyp_bmap;
 		fw_reg_features = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
 		break;
+	case KVM_REG_ARM_VENDOR_HYP_BMAP_2:
+		fw_reg_bmap = &smccc_feat->vendor_hyp_bmap_2;
+		fw_reg_features = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES_2;
+		break;
 	default:
 		return -ENOENT;
 	}
@@ -633,6 +645,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	case KVM_REG_ARM_STD_BMAP:
 	case KVM_REG_ARM_STD_HYP_BMAP:
 	case KVM_REG_ARM_VENDOR_HYP_BMAP:
+	case KVM_REG_ARM_VENDOR_HYP_BMAP_2:
 		return kvm_arm_set_fw_reg_bmap(vcpu, reg->id, val);
 	default:
 		return -ENOENT;
-- 
2.47.0

[PATCH v7 4/5] smccc/kvm_guest: Enable errata based on implementation CPUs

[Shameer Kolothum]

Retrieve any migration target implementation CPUs using the hypercall
and enable associated errata.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 arch/arm64/include/asm/cputype.h    | 24 ++++++++++-
 arch/arm64/include/asm/hypervisor.h |  1 +
 arch/arm64/kernel/cpu_errata.c      | 20 +++++++--
 arch/arm64/kernel/cpufeature.c      |  2 +
 arch/arm64/kernel/image-vars.h      |  2 +
 drivers/firmware/smccc/kvm_guest.c  | 63 +++++++++++++++++++++++++++++
 6 files changed, 107 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 2a76f0e30006..975fbdfc9354 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -267,6 +267,15 @@ struct midr_range {
 #define MIDR_REV(m, v, r) MIDR_RANGE(m, v, r, v, r)
 #define MIDR_ALL_VERSIONS(m) MIDR_RANGE(m, 0, 0, 0xf, 0xf)
 
+struct target_impl_cpu {
+	u64 midr;
+	u64 revidr;
+	u64 aidr;
+};
+
+extern u32 target_impl_cpu_num;
+extern struct target_impl_cpu *target_impl_cpus;
+
 static inline bool midr_is_cpu_model_range(u32 midr, u32 model, u32 rv_min,
 					   u32 rv_max)
 {
@@ -278,8 +287,19 @@ static inline bool midr_is_cpu_model_range(u32 midr, u32 model, u32 rv_min,
 
 static inline bool is_midr_in_range(struct midr_range const *range)
 {
-	return midr_is_cpu_model_range(read_cpuid_id(), range->model,
-				       range->rv_min, range->rv_max);
+	int i;
+
+	if (!target_impl_cpu_num)
+		return midr_is_cpu_model_range(read_cpuid_id(), range->model,
+					       range->rv_min, range->rv_max);
+
+	for (i = 0; i < target_impl_cpu_num; i++) {
+		if (midr_is_cpu_model_range(target_impl_cpus[i].midr,
+					    range->model,
+					    range->rv_min, range->rv_max))
+			return true;
+	}
+	return false;
 }
 
 static inline bool
diff --git a/arch/arm64/include/asm/hypervisor.h b/arch/arm64/include/asm/hypervisor.h
index 409e239834d1..a12fd897c877 100644
--- a/arch/arm64/include/asm/hypervisor.h
+++ b/arch/arm64/include/asm/hypervisor.h
@@ -6,6 +6,7 @@
 
 void kvm_init_hyp_services(void);
 bool kvm_arm_hyp_service_available(u32 func_id);
+void kvm_arm_target_impl_cpu_init(void);
 
 #ifdef CONFIG_ARM_PKVM_GUEST
 void pkvm_init_hyp_services(void);
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 99b55893fc4e..1177a3094cf2 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -14,6 +14,9 @@
 #include <asm/kvm_asm.h>
 #include <asm/smp_plat.h>
 
+u32 target_impl_cpu_num;
+struct target_impl_cpu *target_impl_cpus;
+
 static bool __maybe_unused
 __is_affected_midr_range(const struct arm64_cpu_capabilities *entry,
 			 u32 midr, u32 revidr)
@@ -32,9 +35,20 @@ __is_affected_midr_range(const struct arm64_cpu_capabilities *entry,
 static bool __maybe_unused
 is_affected_midr_range(const struct arm64_cpu_capabilities *entry, int scope)
 {
-	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
-	return __is_affected_midr_range(entry, read_cpuid_id(),
-					read_cpuid(REVIDR_EL1));
+	int i;
+
+	if (!target_impl_cpu_num) {
+		WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
+		return __is_affected_midr_range(entry, read_cpuid_id(),
+						read_cpuid(REVIDR_EL1));
+	}
+
+	for (i = 0; i < target_impl_cpu_num; i++) {
+		if (__is_affected_midr_range(entry, target_impl_cpus[i].midr,
+					     target_impl_cpus[i].midr))
+			return true;
+	}
+	return false;
 }
 
 static bool __maybe_unused
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 72e876f37cd4..5c61d9d9f097 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -86,6 +86,7 @@
 #include <asm/kvm_host.h>
 #include <asm/mmu_context.h>
 #include <asm/mte.h>
+#include <asm/hypervisor.h>
 #include <asm/processor.h>
 #include <asm/smp.h>
 #include <asm/sysreg.h>
@@ -3679,6 +3680,7 @@ unsigned long cpu_get_elf_hwcap3(void)
 
 static void __init setup_boot_cpu_capabilities(void)
 {
+	kvm_arm_target_impl_cpu_init();
 	/*
 	 * The boot CPU's feature register values have been recorded. Detect
 	 * boot cpucaps and local cpucaps for the boot CPU, then enable and
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index ef3a69cc398e..a6926750faaf 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -49,6 +49,8 @@ PROVIDE(__pi_arm64_sw_feature_override	= arm64_sw_feature_override);
 PROVIDE(__pi_arm64_use_ng_mappings	= arm64_use_ng_mappings);
 #ifdef CONFIG_CAVIUM_ERRATUM_27456
 PROVIDE(__pi_cavium_erratum_27456_cpus	= cavium_erratum_27456_cpus);
+PROVIDE(__pi_target_impl_cpu_num	= target_impl_cpu_num);
+PROVIDE(__pi_target_impl_cpus		= target_impl_cpus);
 #endif
 PROVIDE(__pi__ctype			= _ctype);
 PROVIDE(__pi_memstart_offset_seed	= memstart_offset_seed);
diff --git a/drivers/firmware/smccc/kvm_guest.c b/drivers/firmware/smccc/kvm_guest.c
index f3319be20b36..c1d2f28b0f58 100644
--- a/drivers/firmware/smccc/kvm_guest.c
+++ b/drivers/firmware/smccc/kvm_guest.c
@@ -6,8 +6,11 @@
 #include <linux/bitmap.h>
 #include <linux/cache.h>
 #include <linux/kernel.h>
+#include <linux/memblock.h>
 #include <linux/string.h>
 
+#include <uapi/linux/psci.h>
+
 #include <asm/hypervisor.h>
 
 static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };
@@ -51,3 +54,63 @@ bool kvm_arm_hyp_service_available(u32 func_id)
 	return test_bit(func_id, __kvm_arm_hyp_services);
 }
 EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);
+
+void  __init kvm_arm_target_impl_cpu_init(void)
+{
+	int i;
+	u32 ver;
+	u64 max_cpus;
+	struct arm_smccc_res res;
+
+	/* Check we have already set targets */
+	if (target_impl_cpu_num)
+		return;
+
+	if (!kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_VER) ||
+	    !kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_CPUS))
+		return;
+
+	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_VER_FUNC_ID,
+			     0, &res);
+	if (res.a0 != SMCCC_RET_SUCCESS)
+		return;
+
+	/* Version info is in lower 32 bits and is in SMMCCC_VERSION format */
+	ver = lower_32_bits(res.a1);
+	if (PSCI_VERSION_MAJOR(ver) != 1) {
+		pr_warn("Unsupported target CPU implementation version v%d:%d\n",
+			PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
+		return;
+	}
+
+	if (!res.a2) {
+		pr_warn("No target implementation CPUs specified\n");
+		return;
+	}
+
+	max_cpus = res.a2;
+	target_impl_cpus = memblock_alloc(sizeof(*target_impl_cpus) * max_cpus,
+					  __alignof__(*target_impl_cpus));
+	if (!target_impl_cpus) {
+		pr_warn("Not enough memory for struct target_impl_cpu\n");
+		return;
+	}
+
+	for (i = 0; i < max_cpus; i++) {
+		arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID,
+				     i, &res);
+		if (res.a0 != SMCCC_RET_SUCCESS) {
+			memblock_free(target_impl_cpus,
+				      sizeof(*target_impl_cpus) * max_cpus);
+			target_impl_cpus = NULL;
+			pr_warn("Discovering target implementation CPUs failed\n");
+			return;
+		}
+		target_impl_cpus[i].midr = res.a1;
+		target_impl_cpus[i].revidr = res.a2;
+		target_impl_cpus[i].aidr = res.a3;
+	};
+
+	target_impl_cpu_num = max_cpus;
+	pr_info("Number of target implementation CPUs is %d\n", target_impl_cpu_num);
+}
-- 
2.47.0

[PATCH v7 5/5] KVM: selftests: Add test for KVM_REG_ARM_VENDOR_HYP_BMAP_2

[Shameer Kolothum]

One difference here with other pseudo-firmware bitmap registers
is that the default/reset value for the supported hypercall
function-ids is 0 at present. Hence, modify the test accordingly.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 tools/arch/arm64/include/uapi/asm/kvm.h       | 12 +++++
 .../selftests/kvm/arm64/get-reg-list.c        |  1 +
 .../testing/selftests/kvm/arm64/hypercalls.c  | 46 +++++++++++++++----
 3 files changed, 49 insertions(+), 10 deletions(-)

diff --git a/tools/arch/arm64/include/uapi/asm/kvm.h b/tools/arch/arm64/include/uapi/asm/kvm.h
index 66736ff04011..6d44f8c8a18f 100644
--- a/tools/arch/arm64/include/uapi/asm/kvm.h
+++ b/tools/arch/arm64/include/uapi/asm/kvm.h
@@ -374,6 +374,7 @@ enum {
 #endif
 };
 
+/* Vendor hyper call function numbers 0-63 */
 #define KVM_REG_ARM_VENDOR_HYP_BMAP		KVM_REG_ARM_FW_FEAT_BMAP_REG(2)
 
 enum {
@@ -384,6 +385,17 @@ enum {
 #endif
 };
 
+/* Vendor hyper call function numbers 64-127 */
+#define KVM_REG_ARM_VENDOR_HYP_BMAP_2		KVM_REG_ARM_FW_FEAT_BMAP_REG(3)
+
+enum {
+	KVM_REG_ARM_VENDOR_HYP_BIT_DISCOVER_IMPL_VER	= 0,
+	KVM_REG_ARM_VENDOR_HYP_BIT_DISCOVER_IMPL_CPUS	= 1,
+#ifdef __KERNEL__
+	KVM_REG_ARM_VENDOR_HYP_BMAP_2_BIT_COUNT,
+#endif
+};
+
 /* Device Control API on vm fd */
 #define KVM_ARM_VM_SMCCC_CTRL		0
 #define   KVM_ARM_VM_SMCCC_FILTER	0
diff --git a/tools/testing/selftests/kvm/arm64/get-reg-list.c b/tools/testing/selftests/kvm/arm64/get-reg-list.c
index d43fb3f49050..d01798b6b3b4 100644
--- a/tools/testing/selftests/kvm/arm64/get-reg-list.c
+++ b/tools/testing/selftests/kvm/arm64/get-reg-list.c
@@ -332,6 +332,7 @@ static __u64 base_regs[] = {
 	KVM_REG_ARM_FW_FEAT_BMAP_REG(0),	/* KVM_REG_ARM_STD_BMAP */
 	KVM_REG_ARM_FW_FEAT_BMAP_REG(1),	/* KVM_REG_ARM_STD_HYP_BMAP */
 	KVM_REG_ARM_FW_FEAT_BMAP_REG(2),	/* KVM_REG_ARM_VENDOR_HYP_BMAP */
+	KVM_REG_ARM_FW_FEAT_BMAP_REG(3),	/* KVM_REG_ARM_VENDOR_HYP_BMAP_2 */
 	ARM64_SYS_REG(3, 3, 14, 3, 1),	/* CNTV_CTL_EL0 */
 	ARM64_SYS_REG(3, 3, 14, 3, 2),	/* CNTV_CVAL_EL0 */
 	ARM64_SYS_REG(3, 3, 14, 0, 2),
diff --git a/tools/testing/selftests/kvm/arm64/hypercalls.c b/tools/testing/selftests/kvm/arm64/hypercalls.c
index ec54ec7726e9..44cfcf8a7f46 100644
--- a/tools/testing/selftests/kvm/arm64/hypercalls.c
+++ b/tools/testing/selftests/kvm/arm64/hypercalls.c
@@ -21,22 +21,31 @@
 #define KVM_REG_ARM_STD_BMAP_BIT_MAX		0
 #define KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX	0
 #define KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX	1
+#define KVM_REG_ARM_VENDOR_HYP_BMAP_2_BIT_MAX   1
+
+#define KVM_REG_ARM_STD_BMAP_RESET_VAL		FW_REG_ULIMIT_VAL(KVM_REG_ARM_STD_BMAP_BIT_MAX)
+#define KVM_REG_ARM_STD_HYP_BMAP_RESET_VAL	FW_REG_ULIMIT_VAL(KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX)
+#define KVM_REG_ARM_VENDOR_HYP_BMAP_RESET_VAL	FW_REG_ULIMIT_VAL(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX)
+#define KVM_REG_ARM_VENDOR_HYP_BMAP_2_RESET_VAL 0
 
 struct kvm_fw_reg_info {
 	uint64_t reg;		/* Register definition */
 	uint64_t max_feat_bit;	/* Bit that represents the upper limit of the feature-map */
+	uint64_t reset_val;	/* Reset value for the register */
 };
 
 #define FW_REG_INFO(r)			\
 	{					\
 		.reg = r,			\
 		.max_feat_bit = r##_BIT_MAX,	\
+		.reset_val = r##_RESET_VAL	\
 	}
 
 static const struct kvm_fw_reg_info fw_reg_info[] = {
 	FW_REG_INFO(KVM_REG_ARM_STD_BMAP),
 	FW_REG_INFO(KVM_REG_ARM_STD_HYP_BMAP),
 	FW_REG_INFO(KVM_REG_ARM_VENDOR_HYP_BMAP),
+	FW_REG_INFO(KVM_REG_ARM_VENDOR_HYP_BMAP_2),
 };
 
 enum test_stage {
@@ -171,22 +180,39 @@ static void test_fw_regs_before_vm_start(struct kvm_vcpu *vcpu)
 
 	for (i = 0; i < ARRAY_SIZE(fw_reg_info); i++) {
 		const struct kvm_fw_reg_info *reg_info = &fw_reg_info[i];
+		uint64_t set_val;
 
-		/* First 'read' should be an upper limit of the features supported */
+		/* First 'read' should be the reset value for the reg  */
 		val = vcpu_get_reg(vcpu, reg_info->reg);
-		TEST_ASSERT(val == FW_REG_ULIMIT_VAL(reg_info->max_feat_bit),
-			"Expected all the features to be set for reg: 0x%lx; expected: 0x%lx; read: 0x%lx",
-			reg_info->reg, FW_REG_ULIMIT_VAL(reg_info->max_feat_bit), val);
+		TEST_ASSERT(val == reg_info->reset_val,
+			"Unexpected reset value for reg: 0x%lx; expected: 0x%lx; read: 0x%lx",
+			reg_info->reg, reg_info->reset_val, val);
+
+		if (reg_info->reset_val)
+			set_val = 0;
+		else
+			set_val = FW_REG_ULIMIT_VAL(reg_info->max_feat_bit);
 
-		/* Test a 'write' by disabling all the features of the register map */
-		ret = __vcpu_set_reg(vcpu, reg_info->reg, 0);
+		ret = __vcpu_set_reg(vcpu, reg_info->reg, set_val);
 		TEST_ASSERT(ret == 0,
-			"Failed to clear all the features of reg: 0x%lx; ret: %d",
-			reg_info->reg, errno);
+			"Failed to %s all the features of reg: 0x%lx; ret: %d",
+			(set_val ? "set" : "clear"), reg_info->reg, errno);
 
 		val = vcpu_get_reg(vcpu, reg_info->reg);
-		TEST_ASSERT(val == 0,
-			"Expected all the features to be cleared for reg: 0x%lx", reg_info->reg);
+		TEST_ASSERT(val == set_val,
+			"Expected all the features to be %s for reg: 0x%lx",
+			(set_val ? "set" : "cleared"), reg_info->reg);
+
+		/*
+		 * If the reg has been set, clear it as test_fw_regs_after_vm_start()
+		 * expects it to be cleared.
+		 */
+		if (set_val) {
+			ret = __vcpu_set_reg(vcpu, reg_info->reg, 0);
+			TEST_ASSERT(ret == 0,
+			"Failed to clear all the features of reg: 0x%lx; ret: %d",
+			reg_info->reg, errno);
+		}
 
 		/*
 		 * Test enabling a feature that's not supported.
-- 
2.47.0

Re: [PATCH v7 1/5] arm64: Modify _midr_range() functions to read MIDR/REVIDR internally

[Sebastian Ott]

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Hi Shameer,

On Fri, 14 Feb 2025, Shameer Kolothum wrote:
> static inline bool
> -is_midr_in_range_list(u32 midr, struct midr_range const *ranges)
> +is_midr_in_range_list(struct midr_range const *ranges)
> {
> 	while (ranges->model)
> -		if (is_midr_in_range(midr, ranges++))
> +		if (is_midr_in_range(ranges++))
> 			return true;
> 	return false;
> }

There's one more user of this:
drivers/hwtracing/coresight/coresight-etm4x-core.c:1219:13: error: too many arguments to function ‘is_midr_in_range_list’
  1219 |         if (is_midr_in_range_list(read_cpuid_id(), etm_wrong_ccitmin_cpus)) {
       |             ^~~~~~~~~~~~~~~~~~~~~

(sr)

Re: [PATCH v7 4/5] smccc/kvm_guest: Enable errata based on implementation CPUs

[Sebastian Ott]

On Fri, 14 Feb 2025, Shameer Kolothum wrote:
> +++ b/arch/arm64/kernel/cpu_errata.c
> @@ -14,6 +14,9 @@
> #include <asm/kvm_asm.h>
> #include <asm/smp_plat.h>
>
> +u32 target_impl_cpu_num;
> +struct target_impl_cpu *target_impl_cpus;

These should be exported (for configs using
CONFIG_CORESIGHT_SOURCE_ETM4X=m)

Sebastian

Re: [PATCH v7 4/5] smccc/kvm_guest: Enable errata based on implementation CPUs

[Marc Zyngier]

On Fri, 14 Feb 2025 16:12:02 +0000,
Sebastian Ott <sebott@redhat.com> wrote:
> 
> On Fri, 14 Feb 2025, Shameer Kolothum wrote:
> > +++ b/arch/arm64/kernel/cpu_errata.c
> > @@ -14,6 +14,9 @@
> > #include <asm/kvm_asm.h>
> > #include <asm/smp_plat.h>
> > 
> > +u32 target_impl_cpu_num;
> > +struct target_impl_cpu *target_impl_cpus;
> 
> These should be exported (for configs using
> CONFIG_CORESIGHT_SOURCE_ETM4X=m)

It might be better to make is_midr_in_range() out of line, and export
that. This could allow making the data static (by implementing a
couple of additional accessors).

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v7 0/5] KVM: arm64: Errata management for VM Live migration

[Sebastian Ott]

[-- Attachment #1: Type: text/plain, Size: 735 bytes --]

On Fri, 14 Feb 2025, Shameer Kolothum wrote:
> v6-->v7
> https://lore.kernel.org/kvmarm/20250205132222.55816-1-shameerali.kolothum.thodi@huawei.com/
>
> Changes:
>  -Introduced KVM_REG_ARM_VENDOR_HYP_BMAP_2 register for new hypercall
>  support(patch #3)
> -Added selftest for KVM_REG_ARM_VENDOR_HYP_BMAP_2(patch #5).
>
> This can be sanity tested by the Qemu branch here,
> https://github.com/hisilicon/qemu/tree/v9.0-nv-rfcv4-vcpu-model-v2-target-cpu-errata
> (branch based on Eric's/Connie's NV + custom CPU series)
> Eg: to specify target impl CPUs,
> -machine virt,.., x-target-impl-cpus=0xMIDR1:0xREVIDR1-0xMIDR2:REVIDR2
>
> Please take a look and let me know your feedback.

Reviewed-by: Sebastian Ott <sebott@redhat.com>

RE: [PATCH v7 4/5] smccc/kvm_guest: Enable errata based on implementation CPUs

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: Marc Zyngier <maz@kernel.org>
> Sent: Friday, February 14, 2025 4:43 PM
> To: Sebastian Ott <sebott@redhat.com>
> Cc: Shameerali Kolothum Thodi
> <shameerali.kolothum.thodi@huawei.com>; kvmarm@lists.linux.dev;
> oliver.upton@linux.dev; catalin.marinas@arm.com; will@kernel.org;
> mark.rutland@arm.com; cohuck@redhat.com; eric.auger@redhat.com;
> yuzenghui <yuzenghui@huawei.com>; Wangzhou (B)
> <wangzhou1@hisilicon.com>; jiangkunkun <jiangkunkun@huawei.com>;
> Jonathan Cameron <jonathan.cameron@huawei.com>; Anthony Jebson
> <anthony.jebson@huawei.com>; linux-arm-kernel@lists.infradead.org;
> Linuxarm <linuxarm@huawei.com>
> Subject: Re: [PATCH v7 4/5] smccc/kvm_guest: Enable errata based on
> implementation CPUs
> 
> On Fri, 14 Feb 2025 16:12:02 +0000,
> Sebastian Ott <sebott@redhat.com> wrote:
> >
> > On Fri, 14 Feb 2025, Shameer Kolothum wrote:
> > > +++ b/arch/arm64/kernel/cpu_errata.c
> > > @@ -14,6 +14,9 @@
> > > #include <asm/kvm_asm.h>
> > > #include <asm/smp_plat.h>
> > >
> > > +u32 target_impl_cpu_num;
> > > +struct target_impl_cpu *target_impl_cpus;
> >
> > These should be exported (for configs using
> > CONFIG_CORESIGHT_SOURCE_ETM4X=m)

Thanks Sebastian. I missed that.

> 
> It might be better to make is_midr_in_range() out of line, and export
> that. This could allow making the data static (by implementing a
> couple of additional accessors).

Ok. I will give it a go.

Thanks,
Shameer