packages/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
qemu/target-arm-Read-debug-related-ID-registers-from-KVM.patch
Peng Liang 0c39e725b0 target/arm: backport upstream patches to support CPU feature 
To support CPU feature in AArch64, we need to move some field from
ARMCPU to ARMISARegisters, add more definitions of ID fields, and add
suport query-cpu-model-expansion qmp command.  Let's backport upstream
patches to do these.

Signed-off-by: Peng Liang <liangpeng10@huawei.com>
2020-08-19 12:36:09 +08:00

132 lines
5.9 KiB
Diff
Raw Blame History

From 9cda8af5af9e95e7b0ff683d0fb661c1ffcba8d8 Mon Sep 17 00:00:00 2001
From: Peter Maydell <peter.maydell@linaro.org>
Date: Fri, 14 Feb 2020 17:51:07 +0000
Subject: [PATCH 11/13] target/arm: Read debug-related ID registers from KVM
Now we have isar_feature test functions that look at fields in the
ID_AA64DFR0_EL1 and ID_DFR0 ID registers, add the code that reads
these register values from KVM so that the checks behave correctly
when we're using KVM.
No isar_feature function tests ID_AA64DFR1_EL1 or DBGDIDR yet, but we
add it to maintain the invariant that every field in the
ARMISARegisters struct is populated for a KVM CPU and can be relied
on. This requirement isn't actually written down yet, so add a note
to the relevant comment.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200214175116.9164-13-peter.maydell@linaro.org
---
target/arm/cpu.h | 5 +++++
target/arm/kvm32.c | 8 ++++++++
target/arm/kvm64.c | 36 ++++++++++++++++++++++++++++++++++++
3 files changed, 49 insertions(+)
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index a78c30c3..56d8cd8c 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -848,6 +848,11 @@ struct ARMCPU {
* prefix means a constant register.
* Some of these registers are split out into a substructure that
* is shared with the translators to control the ISA.
+ *
+ * Note that if you add an ID register to the ARMISARegisters struct
+ * you need to also update the 32-bit and 64-bit versions of the
+ * kvm_arm_get_host_cpu_features() function to correctly populate the
+ * field by reading the value from the KVM vCPU.
*/
struct ARMISARegisters {
uint32_t id_isar0;
diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c
index 2247148e..e984d52d 100644
--- a/target/arm/kvm32.c
+++ b/target/arm/kvm32.c
@@ -93,6 +93,9 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
ahcf->isar.id_isar6 = 0;
}
+ err |= read_sys_reg32(fdarray[2], &ahcf->isar.id_dfr0,
+ ARM_CP15_REG32(0, 0, 1, 2));
+
err |= read_sys_reg32(fdarray[2], &ahcf->isar.mvfr0,
KVM_REG_ARM | KVM_REG_SIZE_U32 |
KVM_REG_ARM_VFP | KVM_REG_ARM_VFP_MVFR0);
@@ -121,6 +124,11 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
ahcf->isar.id_mmfr4 = 0;
}
+ /*
+ * There is no way to read DBGDIDR, because currently 32-bit KVM
+ * doesn't implement debug at all. Leave it at zero.
+ */
+
kvm_arm_destroy_scratch_host_vcpu(fdarray);
if (err < 0) {
diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 276d1466..2a88b8df 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -533,6 +533,10 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
} else {
err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64pfr1,
ARM64_SYS_REG(3, 0, 0, 4, 1));
+ err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64dfr0,
+ ARM64_SYS_REG(3, 0, 0, 5, 0));
+ err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64dfr1,
+ ARM64_SYS_REG(3, 0, 0, 5, 1));
err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64isar0,
ARM64_SYS_REG(3, 0, 0, 6, 0));
err |= read_sys_reg64(fdarray[2], &ahcf->isar.id_aa64isar1,
@@ -551,6 +555,8 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
* than skipping the reads and leaving 0, as we must avoid
* considering the values in every case.
*/
+ err |= read_sys_reg32(fdarray[2], &ahcf->isar.id_dfr0,
+ ARM64_SYS_REG(3, 0, 0, 1, 2));
err |= read_sys_reg32(fdarray[2], &ahcf->isar.id_mmfr0,
ARM64_SYS_REG(3, 0, 0, 1, 4));
err |= read_sys_reg32(fdarray[2], &ahcf->isar.id_mmfr1,
@@ -582,6 +588,36 @@ bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
ARM64_SYS_REG(3, 0, 0, 3, 1));
err |= read_sys_reg32(fdarray[2], &ahcf->isar.mvfr2,
ARM64_SYS_REG(3, 0, 0, 3, 2));
+
+ /*
+ * DBGDIDR is a bit complicated because the kernel doesn't
+ * provide an accessor for it in 64-bit mode, which is what this
+ * scratch VM is in, and there's no architected "64-bit sysreg
+ * which reads the same as the 32-bit register" the way there is
+ * for other ID registers. Instead we synthesize a value from the
+ * AArch64 ID_AA64DFR0, the same way the kernel code in
+ * arch/arm64/kvm/sys_regs.c:trap_dbgidr() does.
+ * We only do this if the CPU supports AArch32 at EL1.
+ */
+ if (FIELD_EX32(ahcf->isar.id_aa64pfr0, ID_AA64PFR0, EL1) >= 2) {
+ int wrps = FIELD_EX64(ahcf->isar.id_aa64dfr0, ID_AA64DFR0, WRPS);
+ int brps = FIELD_EX64(ahcf->isar.id_aa64dfr0, ID_AA64DFR0, BRPS);
+ int ctx_cmps =
+ FIELD_EX64(ahcf->isar.id_aa64dfr0, ID_AA64DFR0, CTX_CMPS);
+ int version = 6; /* ARMv8 debug architecture */
+ bool has_el3 =
+ !!FIELD_EX32(ahcf->isar.id_aa64pfr0, ID_AA64PFR0, EL3);
+ uint32_t dbgdidr = 0;
+
+ dbgdidr = FIELD_DP32(dbgdidr, DBGDIDR, WRPS, wrps);
+ dbgdidr = FIELD_DP32(dbgdidr, DBGDIDR, BRPS, brps);
+ dbgdidr = FIELD_DP32(dbgdidr, DBGDIDR, CTX_CMPS, ctx_cmps);
+ dbgdidr = FIELD_DP32(dbgdidr, DBGDIDR, VERSION, version);
+ dbgdidr = FIELD_DP32(dbgdidr, DBGDIDR, NSUHD_IMP, has_el3);
+ dbgdidr = FIELD_DP32(dbgdidr, DBGDIDR, SE_IMP, has_el3);
+ dbgdidr |= (1 << 15); /* RES1 bit */
+ ahcf->isar.dbgdidr = dbgdidr;
+ }
}
kvm_arm_destroy_scratch_host_vcpu(fdarray);
--
2.25.1
Reference in New Issue View Git Blame Copy Permalink