Conversion between KVM system registers ids and the HVF system
register ids is trivial.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
target/arm/hvf/hvf.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index f0e4b75e6a..2577dc1c0c 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -403,6 +403,26 @@ struct hvf_sreg_match {
uint32_t cp_idx;
};
+/*
+ * QEMU uses KVM system register ids in the migration format.
+ * Conveniently, HVF uses the same encoding of the op* and cr* parameters
+ * within the low 16 bits of the ids. Thus conversion between the
+ * formats is trivial.
+ */
+
+#define KVMID_TO_HVF(KVM) ((KVM) & 0xffff)
+#define HVF_TO_KVMID(HVF) \
+ (CP_REG_ARM64 | CP_REG_SIZE_U64 | CP_REG_ARM64_SYSREG | (HVF))
+
+/* Verify this at compile-time. */
+
+#define DEF_SYSREG(HVF_ID, ...) \
+ QEMU_BUILD_BUG_ON(HVF_ID != KVMID_TO_HVF(KVMID_AA64_SYS_REG64(__VA_ARGS__)));
+
+#include "sysreg.c.inc"
+
+#undef DEF_SYSREG
+
#define DEF_SYSREG(HVF_ID, crn, crm, op0, op1, op2) \
{ HVF_ID, HVF_SYSREG(crn, crm, op0, op1, op2) },
--
2.43.0On 18/8/25 06:13, Richard Henderson wrote:
> Conversion between KVM system registers ids and the HVF system
> register ids is trivial.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> target/arm/hvf/hvf.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
> index f0e4b75e6a..2577dc1c0c 100644
> --- a/target/arm/hvf/hvf.c
> +++ b/target/arm/hvf/hvf.c
> @@ -403,6 +403,26 @@ struct hvf_sreg_match {
> uint32_t cp_idx;
> };
>
> +/*
> + * QEMU uses KVM system register ids in the migration format.
> + * Conveniently, HVF uses the same encoding of the op* and cr* parameters
> + * within the low 16 bits of the ids. Thus conversion between the
> + * formats is trivial.
> + */
> +
> +#define KVMID_TO_HVF(KVM) ((KVM) & 0xffff)
> +#define HVF_TO_KVMID(HVF) \
> + (CP_REG_ARM64 | CP_REG_SIZE_U64 | CP_REG_ARM64_SYSREG | (HVF))
> +
> +/* Verify this at compile-time. */
> +
> +#define DEF_SYSREG(HVF_ID, ...) \
> + QEMU_BUILD_BUG_ON(HVF_ID != KVMID_TO_HVF(KVMID_AA64_SYS_REG64(__VA_ARGS__)));
Rebasing Mohamed's work I'm getting:
In file included from ../../target/arm/hvf/hvf.c:413:
../../target/arm/hvf/sysreg.c.inc:156:1: error: static assertion failed
due to requirement '!(HV_SYS_REG_MDCR_EL2 != (((((1 << 28) | (19 << 16)
| ((3) << 14) | ((4) << 11) | ((1) << 7) | ((1) << 3) | ((1) << 0)) |
13510798882111488ULL)) & 65535))': not expecting: HV_SYS_REG_MDCR_EL2 !=
KVMID_TO_HVF(KVMID_AA64_SYS_REG64(1, 1, 3, 4, 1))
156 | DEF_SYSREG(HV_SYS_REG_MDCR_EL2, 1, 1, 3, 4, 1)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Having in <Hypervisor.h> -> <Hypervisor/hv_vcpu_types.h>:
// Exception Level 2 (EL2) registers.
// These registers are only available if EL2 was enabled in the VM
configuration.
HV_SYS_REG_CNTHCTL_EL2 = 0xe708,
HV_SYS_REG_CNTHP_CTL_EL2 = 0xe711,
HV_SYS_REG_CNTHP_CVAL_EL2 = 0xe712,
HV_SYS_REG_CNTHP_TVAL_EL2 = 0xe710,
HV_SYS_REG_CNTVOFF_EL2 = 0xe703,
HV_SYS_REG_CPTR_EL2 = 0xe08a,
HV_SYS_REG_ELR_EL2 = 0xe201,
HV_SYS_REG_ESR_EL2 = 0xe290,
HV_SYS_REG_FAR_EL2 = 0xe300,
HV_SYS_REG_HCR_EL2 = 0xe088,
HV_SYS_REG_HPFAR_EL2 = 0xe304,
HV_SYS_REG_MAIR_EL2 = 0xe510,
HV_SYS_REG_MDCR_EL2 = 0xe019, <----
HV_SYS_REG_SCTLR_EL2 = 0xe080,
HV_SYS_REG_SPSR_EL2 = 0xe200,
HV_SYS_REG_SP_EL2 = 0xf208,
HV_SYS_REG_TCR_EL2 = 0xe102,
HV_SYS_REG_TPIDR_EL2 = 0xe682,
HV_SYS_REG_TTBR0_EL2 = 0xe100,
HV_SYS_REG_TTBR1_EL2 = 0xe101,
HV_SYS_REG_VBAR_EL2 = 0xe600,
HV_SYS_REG_VMPIDR_EL2 = 0xe005,
HV_SYS_REG_VPIDR_EL2 = 0xe000,
HV_SYS_REG_VTCR_EL2 = 0xe10a,
HV_SYS_REG_VTTBR_EL2 = 0xe108,
> +
> +#include "sysreg.c.inc"
> +
> +#undef DEF_SYSREG
> +
> #define DEF_SYSREG(HVF_ID, crn, crm, op0, op1, op2) \
> { HVF_ID, HVF_SYSREG(crn, crm, op0, op1, op2) },
>
On 8/18/25 22:41, Philippe Mathieu-Daudé wrote: > Rebasing Mohamed's work I'm getting: > > In file included from ../../target/arm/hvf/hvf.c:413: > ../../target/arm/hvf/sysreg.c.inc:156:1: error: static assertion failed due to requirement > '!(HV_SYS_REG_MDCR_EL2 != (((((1 << 28) | (19 << 16) | ((3) << 14) | ((4) << 11) | ((1) << > 7) | ((1) << 3) | ((1) << 0)) | 13510798882111488ULL)) & 65535))': not expecting: > HV_SYS_REG_MDCR_EL2 != KVMID_TO_HVF(KVMID_AA64_SYS_REG64(1, 1, 3, 4, 1)) > 156 | DEF_SYSREG(HV_SYS_REG_MDCR_EL2, 1, 1, 3, 4, 1) > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > HV_SYS_REG_MDCR_EL2 = 0xe019, <---- How odd. It should be e089, if it were encoded like all the others. I wonder if this is a manual typo that's now baked into the api, or if it's an OS bug. r~
Cc'ing Apple folks hoping they can forward or directly help :) On 18/8/25 15:21, Richard Henderson wrote: > On 8/18/25 22:41, Philippe Mathieu-Daudé wrote: >> Rebasing Mohamed's work I'm getting: >> >> In file included from ../../target/arm/hvf/hvf.c:413: >> ../../target/arm/hvf/sysreg.c.inc:156:1: error: static assertion >> failed due to requirement '!(HV_SYS_REG_MDCR_EL2 != (((((1 << 28) | >> (19 << 16) | ((3) << 14) | ((4) << 11) | ((1) << 7) | ((1) << 3) | >> ((1) << 0)) | 13510798882111488ULL)) & 65535))': not expecting: >> HV_SYS_REG_MDCR_EL2 != KVMID_TO_HVF(KVMID_AA64_SYS_REG64(1, 1, 3, 4, 1)) >> 156 | DEF_SYSREG(HV_SYS_REG_MDCR_EL2, 1, 1, 3, 4, 1) >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > >> HV_SYS_REG_MDCR_EL2 = 0xe019, <---- > > How odd. It should be e089, if it were encoded like all the others. > > I wonder if this is a manual typo that's now baked into the api, or if > it's an OS bug. > > > r~ >
Howdy, On macOS versions/SDKs before 26 you are correct, we had an invalid enum value for HV_SYS_REG_MDCR_EL2 in the API, but the hv_vcpu_get/set_sys_reg APIs work with this value even though the encoding is incorrect. The enum value has been remedied in 26+ (0xe089 as you pointed out) and has been done in a backwards compatible way internally in the framework. > On Aug 18, 2025, at 8:46 AM, Philippe Mathieu-Daudé <philmd@linaro.org> wrote: > > Cc'ing Apple folks hoping they can forward or directly help :) > > On 18/8/25 15:21, Richard Henderson wrote: >> On 8/18/25 22:41, Philippe Mathieu-Daudé wrote: >>> Rebasing Mohamed's work I'm getting: >>> >>> In file included from ../../target/arm/hvf/hvf.c:413: >>> ../../target/arm/hvf/sysreg.c.inc:156:1: error: static assertion failed due to requirement '!(HV_SYS_REG_MDCR_EL2 != (((((1 << 28) | (19 << 16) | ((3) << 14) | ((4) << 11) | ((1) << 7) | ((1) << 3) | ((1) << 0)) | 13510798882111488ULL)) & 65535))': not expecting: HV_SYS_REG_MDCR_EL2 != KVMID_TO_HVF(KVMID_AA64_SYS_REG64(1, 1, 3, 4, 1)) >>> 156 | DEF_SYSREG(HV_SYS_REG_MDCR_EL2, 1, 1, 3, 4, 1) >>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> HV_SYS_REG_MDCR_EL2 = 0xe019, <---- >> How odd. It should be e089, if it were encoded like all the others. >> I wonder if this is a manual typo that's now baked into the api, or if it's an OS bug. >> r~ >
On 18/8/25 20:37, Danny Canter wrote:
> Howdy,
>
> On macOS versions/SDKs before 26 you are correct, we had an invalid enum
> value for HV_SYS_REG_MDCR_EL2 in the API, but the hv_vcpu_get/
> set_sys_reg APIs work with this value even though the
> encoding is incorrect. The enum value has been remedied in 26+ (0xe089
> as you pointed out) and has been done in a backwards compatible way
> internally in the framework.
Thanks Danny!
Richard, should we guard the QEMU_BUILD_BUG_ON() macro with:
#if defined(MAC_OS_VERSION_26_0) && \
MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_26_0
?
>
>> On Aug 18, 2025, at 8:46 AM, Philippe Mathieu-Daudé
>> <philmd@linaro.org> wrote:
>>
>> Cc'ing Apple folks hoping they can forward or directly help :)
>>
>> On 18/8/25 15:21, Richard Henderson wrote:
>>> On 8/18/25 22:41, Philippe Mathieu-Daudé wrote:
>>>> Rebasing Mohamed's work I'm getting:
>>>>
>>>> In file included from ../../target/arm/hvf/hvf.c:413:
>>>> ../../target/arm/hvf/sysreg.c.inc:156:1: error: static assertion
>>>> failed due to requirement '!(HV_SYS_REG_MDCR_EL2 != (((((1 << 28) |
>>>> (19 << 16) | ((3) << 14) | ((4) << 11) | ((1) << 7) | ((1) << 3) |
>>>> ((1) << 0)) | 13510798882111488ULL)) & 65535))': not expecting:
>>>> HV_SYS_REG_MDCR_EL2 != KVMID_TO_HVF(KVMID_AA64_SYS_REG64(1, 1, 3, 4, 1))
>>>> 156 | DEF_SYSREG(HV_SYS_REG_MDCR_EL2, 1, 1, 3, 4, 1)
>>>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>> HV_SYS_REG_MDCR_EL2 = 0xe019, <----
>>> How odd. It should be e089, if it were encoded like all the others.
>>> I wonder if this is a manual typo that's now baked into the api, or
>>> if it's an OS bug.
>>> r~
>>
>
On 9/1/25 01:02, Philippe Mathieu-Daudé wrote: > On 18/8/25 20:37, Danny Canter wrote: >> Howdy, >> >> On macOS versions/SDKs before 26 you are correct, we had an invalid enum value for >> HV_SYS_REG_MDCR_EL2 in the API, but the hv_vcpu_get/ set_sys_reg APIs work with this >> value even though the >> encoding is incorrect. The enum value has been remedied in 26+ (0xe089 as you pointed >> out) and has been done in a backwards compatible way internally in the framework. > > Thanks Danny! > > Richard, should we guard the QEMU_BUILD_BUG_ON() macro with: > > #if defined(MAC_OS_VERSION_26_0) && \ > MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_26_0 > > ? That's one possibility. Another is to remap the one broken enum, since this fix is described to be backward compatible. r~
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