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From: Mohamed Mediouni <mohamed@unpredictable.fr>
To: qemu-devel@nongnu.org
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Shannon Zhao" <shannon.zhaosl@gmail.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"Ani Sinha" <anisinha@redhat.com>,
	qemu-arm@nongnu.org, "Paolo Bonzini" <pbonzini@redhat.com>,
	"Roman Bolshakov" <rbolshakov@ddn.com>,
	"Igor Mammedov" <imammedo@redhat.com>,
	"Phil Dennis-Jordan" <phil@philjordan.eu>,
	"Alexander Graf" <agraf@csgraf.de>,
	"Mads Ynddal" <mads@ynddal.dk>,
	"Cameron Esfahani" <dirty@apple.com>,
	"Mohamed Mediouni" <mohamed@unpredictable.fr>,
	"Philippe Mathieu-Daudé" <philmd@linaro.org>
Subject: [PATCH v6 02/13] hvf: switch hvf_arm_get_host_cpu_features to not create a vCPU
Date: Fri,  8 Aug 2025 09:01:26 +0200	[thread overview]
Message-ID: <20250808070137.48716-3-mohamed@unpredictable.fr> (raw)
In-Reply-To: <20250808070137.48716-1-mohamed@unpredictable.fr>

Creating a vCPU locks out APIs such as hv_gic_create().

As a result, switch to using the hv_vcpu_config_get_feature_reg interface.

Hardcode MIDR because Apple deliberately doesn't expose a divergent MIDR across systems.

Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 target/arm/hvf/hvf.c | 36 +++++++++++++++---------------------
 1 file changed, 15 insertions(+), 21 deletions(-)

diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index 47b0cd3a35..460782dbc0 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -864,24 +864,24 @@ static bool hvf_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
 {
     ARMISARegisters host_isar = {};
     const struct isar_regs {
-        int reg;
+        hv_feature_reg_t reg;
         uint64_t *val;
     } regs[] = {
-        { HV_SYS_REG_ID_AA64PFR0_EL1, &host_isar.idregs[ID_AA64PFR0_EL1_IDX] },
-        { HV_SYS_REG_ID_AA64PFR1_EL1, &host_isar.idregs[ID_AA64PFR1_EL1_IDX] },
-        { HV_SYS_REG_ID_AA64DFR0_EL1, &host_isar.idregs[ID_AA64DFR0_EL1_IDX] },
-        { HV_SYS_REG_ID_AA64DFR1_EL1, &host_isar.idregs[ID_AA64DFR1_EL1_IDX] },
-        { HV_SYS_REG_ID_AA64ISAR0_EL1, &host_isar.idregs[ID_AA64ISAR0_EL1_IDX] },
-        { HV_SYS_REG_ID_AA64ISAR1_EL1, &host_isar.idregs[ID_AA64ISAR1_EL1_IDX] },
+        { HV_FEATURE_REG_ID_AA64PFR0_EL1, &host_isar.idregs[ID_AA64PFR0_EL1_IDX] },
+        { HV_FEATURE_REG_ID_AA64PFR1_EL1, &host_isar.idregs[ID_AA64PFR1_EL1_IDX] },
+        { HV_FEATURE_REG_ID_AA64DFR0_EL1, &host_isar.idregs[ID_AA64DFR0_EL1_IDX] },
+        { HV_FEATURE_REG_ID_AA64DFR1_EL1, &host_isar.idregs[ID_AA64DFR1_EL1_IDX] },
+        { HV_FEATURE_REG_ID_AA64ISAR0_EL1, &host_isar.idregs[ID_AA64ISAR0_EL1_IDX] },
+        { HV_FEATURE_REG_ID_AA64ISAR1_EL1, &host_isar.idregs[ID_AA64ISAR1_EL1_IDX] },
         /* Add ID_AA64ISAR2_EL1 here when HVF supports it */
-        { HV_SYS_REG_ID_AA64MMFR0_EL1, &host_isar.idregs[ID_AA64MMFR0_EL1_IDX] },
-        { HV_SYS_REG_ID_AA64MMFR1_EL1, &host_isar.idregs[ID_AA64MMFR1_EL1_IDX] },
-        { HV_SYS_REG_ID_AA64MMFR2_EL1, &host_isar.idregs[ID_AA64MMFR2_EL1_IDX] },
+        { HV_FEATURE_REG_ID_AA64MMFR0_EL1, &host_isar.idregs[ID_AA64MMFR0_EL1_IDX] },
+        { HV_FEATURE_REG_ID_AA64MMFR1_EL1, &host_isar.idregs[ID_AA64MMFR1_EL1_IDX] },
+        { HV_FEATURE_REG_ID_AA64MMFR2_EL1, &host_isar.idregs[ID_AA64MMFR2_EL1_IDX] },
         /* Add ID_AA64MMFR3_EL1 here when HVF supports it */
     };
-    hv_vcpu_t fd;
+
     hv_return_t r = HV_SUCCESS;
-    hv_vcpu_exit_t *exit;
+    hv_vcpu_config_t hv_vcpu_config = hv_vcpu_config_create();
     int i;
 
     ahcf->dtb_compatible = "arm,armv8";
@@ -891,17 +891,11 @@ static bool hvf_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
                      (1ULL << ARM_FEATURE_PMU) |
                      (1ULL << ARM_FEATURE_GENERIC_TIMER);
 
-    /* We set up a small vcpu to extract host registers */
-
-    if (hv_vcpu_create(&fd, &exit, NULL) != HV_SUCCESS) {
-        return false;
-    }
-
     for (i = 0; i < ARRAY_SIZE(regs); i++) {
-        r |= hv_vcpu_get_sys_reg(fd, regs[i].reg, regs[i].val);
+        r |= hv_vcpu_config_get_feature_reg(hv_vcpu_config, regs[i].reg, regs[i].val);
     }
-    r |= hv_vcpu_get_sys_reg(fd, HV_SYS_REG_MIDR_EL1, &ahcf->midr);
-    r |= hv_vcpu_destroy(fd);
+    /* post-Armv6, Vendor: Apple (0x61), model and revision not set (all zeroes) */
+    ahcf->midr = 0x610f0000;
 
     clamp_id_aa64mmfr0_parange_to_ipa_size(&host_isar);
 
-- 
2.39.5 (Apple Git-154)



  parent reply	other threads:[~2025-08-08  7:03 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-08  7:01 [PATCH v6 00/13] HVF: Add support for platform vGIC and nested virtualisation Mohamed Mediouni
2025-08-08  7:01 ` [PATCH v6 01/13] hw/arm: virt: add GICv2m for the case when ITS is not available Mohamed Mediouni
2025-08-08  7:01 ` Mohamed Mediouni [this message]
2025-08-20 12:29   ` [PATCH v6 02/13] hvf: switch hvf_arm_get_host_cpu_features to not create a vCPU Mads Ynddal
2025-08-08  7:01 ` [PATCH v6 03/13] accel, hw/arm, include/system/hvf: infrastructure changes for HVF vGIC Mohamed Mediouni
2025-08-12 13:05   ` Philippe Mathieu-Daudé
2025-08-08  7:01 ` [PATCH v6 04/13] hw/intc: Add hvf vGIC interrupt controller support Mohamed Mediouni
2025-08-12 16:19   ` Philippe Mathieu-Daudé
2025-08-14 12:57   ` Mads Ynddal
2025-08-15  5:55     ` Mohamed Mediouni
2025-08-19 13:21       ` Mads Ynddal
2025-08-08  7:01 ` [PATCH v6 05/13] hw/arm, target/arm: nested virtualisation on HVF Mohamed Mediouni
2025-08-11 12:47   ` Philippe Mathieu-Daudé
2025-08-11 13:35     ` Mohamed Mediouni
2025-08-11 13:40       ` Philippe Mathieu-Daudé
2025-08-11 12:56   ` Philippe Mathieu-Daudé
2025-08-11 13:13     ` Philippe Mathieu-Daudé
2025-08-11 13:35     ` Mohamed Mediouni
2025-08-08  7:01 ` [PATCH v6 06/13] hvf: save/restore Apple GIC state Mohamed Mediouni
2025-08-08  7:01 ` [PATCH v6 07/13] target/arm: hvf: pass through CNTHCTL_EL2 and MDCCINT_EL1 Mohamed Mediouni
2025-08-08  7:01 ` [PATCH v6 08/13] hw/arm: virt: cleanly fail on attempt to use the platform vGIC together with ITS Mohamed Mediouni
2025-08-08  7:01 ` [PATCH v6 09/13] hvf: only call hvf_sync_vtimer() when running without the platform vGIC Mohamed Mediouni
2025-08-19 12:37   ` Mads Ynddal
2025-08-08  7:01 ` [PATCH v6 10/13] hvf: sync registers used at EL2 Mohamed Mediouni
2025-08-08  7:01 ` [PATCH v6 11/13] hvf: gate ARM_FEATURE_PMU register emulation behind not being " Mohamed Mediouni
2025-08-08  7:01 ` [PATCH v6 12/13] target/arm: hvf: instantiate GIC early Mohamed Mediouni
2025-08-14 13:06   ` Mads Ynddal
2025-08-08  7:01 ` [PATCH v6 13/13] target/arm: hvf: add asserts for code paths not leveraged when using the vGIC Mohamed Mediouni
2025-08-19 12:22   ` Mads Ynddal

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