[PATCH 0/8] target/arm: Implement FEAT_ECV (Enhanced Counter Virtualization)

[PATCH 0/8] target/arm: Implement FEAT_ECV (Enhanced Counter Virtualization)

[Peter Maydell]

This patchset implements the Arm FEAT_ECV architectural feature, which provides:
 * some new trap bits for hypervisors to trap accesses to various
   counter and timer registers
 * support for scaling of the event stream for the guest (which we don't
   need to implement because our events are always nops)
 * new registers CNTPCTSS_EL0 and NCTVCTSS_EL0 which are
   "self-sychronizing" views of the CNTPCT_EL0 and CNTVCT_EL0, meaning
   that no barriers are needed around their accesses. For us these
   are just the same as the normal views, because all our sysregs are
   inherently self-sychronizing.
 * a new register CNTPOFF_EL2, which allows the hypervisor to set
   an adjustable offset for what the guest sees in the physical
   timer and counter (similar to the existing CNTVOFF_EL2 for the
   virtual timer and counter)

These patchsets implement support for this and enable them in the 'max' CPU.
At the start of the series there's one patch doing some "move things to a
better header file" and one bugfix for a "no sensible guest should ever
do this" corner case.

I'm hoping we can get these reviewed in time to get them in before
softfreeze.

thanks
-- PMM

Peter Maydell (8):
  target/arm: Move some register related defines to internals.h
  target/arm: Timer _EL02 registers UNDEF for E2H == 0
  target/arm: use FIELD macro for CNTHCTL bit definitions
  target/arm: Don't allow RES0 CNTHCTL_EL2 bits to be written
  target/arm: Implement new FEAT_ECV trap bits
  target/arm: Define CNTPCTSS_EL0 and CNTVCTSS_EL0
  target/arm: Implement FEAT_ECV CNTPOFF_EL2 handling
  target/arm: Enable FEAT_ECV for 'max' CPU

 docs/system/arm/emulation.rst |   1 +
 target/arm/cpu-features.h     |  10 ++
 target/arm/cpu.h              | 129 +----------------------
 target/arm/internals.h        | 143 +++++++++++++++++++++++++
 target/arm/helper.c           | 189 +++++++++++++++++++++++++++++++---
 target/arm/tcg/cpu64.c        |   1 +
 target/arm/trace-events       |   1 +
 7 files changed, 334 insertions(+), 140 deletions(-)

-- 
2.34.1

[PATCH 1/8] target/arm: Move some register related defines to internals.h

[Peter Maydell]

cpu.h has a lot of #defines relating to CPU register fields.
Most of these aren't actually used outside target/arm code,
so there's no point in cluttering up the cpu.h file with them.
Move some easy ones to internals.h.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
I want to add some more CNTHCTL_* values, and don't really
want to put more into cpu.h. There's obviously more that could
be moved here, but I don't want to get into doing too much
all at once. I pondered having a different file for these,
but probably we'd end up pulling it in everywhere we do
internals.h.
---
 target/arm/cpu.h       | 128 -----------------------------------------
 target/arm/internals.h | 128 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 128 insertions(+), 128 deletions(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 63f31e0d984..3cbfd4f9a74 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -141,11 +141,6 @@ typedef struct ARMGenericTimer {
     uint64_t ctl; /* Timer Control register */
 } ARMGenericTimer;
 
-#define VTCR_NSW (1u << 29)
-#define VTCR_NSA (1u << 30)
-#define VSTCR_SW VTCR_NSW
-#define VSTCR_SA VTCR_NSA
-
 /* Define a maximum sized vector register.
  * For 32-bit, this is a 128-bit NEON/AdvSIMD register.
  * For 64-bit, this is a 2048-bit SVE register.
@@ -1382,73 +1377,6 @@ void pmu_init(ARMCPU *cpu);
 #define SCTLR_SPINTMASK (1ULL << 62) /* FEAT_NMI */
 #define SCTLR_TIDCP   (1ULL << 63) /* FEAT_TIDCP1 */
 
-/* Bit definitions for CPACR (AArch32 only) */
-FIELD(CPACR, CP10, 20, 2)
-FIELD(CPACR, CP11, 22, 2)
-FIELD(CPACR, TRCDIS, 28, 1)    /* matches CPACR_EL1.TTA */
-FIELD(CPACR, D32DIS, 30, 1)    /* up to v7; RAZ in v8 */
-FIELD(CPACR, ASEDIS, 31, 1)
-
-/* Bit definitions for CPACR_EL1 (AArch64 only) */
-FIELD(CPACR_EL1, ZEN, 16, 2)
-FIELD(CPACR_EL1, FPEN, 20, 2)
-FIELD(CPACR_EL1, SMEN, 24, 2)
-FIELD(CPACR_EL1, TTA, 28, 1)   /* matches CPACR.TRCDIS */
-
-/* Bit definitions for HCPTR (AArch32 only) */
-FIELD(HCPTR, TCP10, 10, 1)
-FIELD(HCPTR, TCP11, 11, 1)
-FIELD(HCPTR, TASE, 15, 1)
-FIELD(HCPTR, TTA, 20, 1)
-FIELD(HCPTR, TAM, 30, 1)       /* matches CPTR_EL2.TAM */
-FIELD(HCPTR, TCPAC, 31, 1)     /* matches CPTR_EL2.TCPAC */
-
-/* Bit definitions for CPTR_EL2 (AArch64 only) */
-FIELD(CPTR_EL2, TZ, 8, 1)      /* !E2H */
-FIELD(CPTR_EL2, TFP, 10, 1)    /* !E2H, matches HCPTR.TCP10 */
-FIELD(CPTR_EL2, TSM, 12, 1)    /* !E2H */
-FIELD(CPTR_EL2, ZEN, 16, 2)    /* E2H */
-FIELD(CPTR_EL2, FPEN, 20, 2)   /* E2H */
-FIELD(CPTR_EL2, SMEN, 24, 2)   /* E2H */
-FIELD(CPTR_EL2, TTA, 28, 1)
-FIELD(CPTR_EL2, TAM, 30, 1)    /* matches HCPTR.TAM */
-FIELD(CPTR_EL2, TCPAC, 31, 1)  /* matches HCPTR.TCPAC */
-
-/* Bit definitions for CPTR_EL3 (AArch64 only) */
-FIELD(CPTR_EL3, EZ, 8, 1)
-FIELD(CPTR_EL3, TFP, 10, 1)
-FIELD(CPTR_EL3, ESM, 12, 1)
-FIELD(CPTR_EL3, TTA, 20, 1)
-FIELD(CPTR_EL3, TAM, 30, 1)
-FIELD(CPTR_EL3, TCPAC, 31, 1)
-
-#define MDCR_MTPME    (1U << 28)
-#define MDCR_TDCC     (1U << 27)
-#define MDCR_HLP      (1U << 26)  /* MDCR_EL2 */
-#define MDCR_SCCD     (1U << 23)  /* MDCR_EL3 */
-#define MDCR_HCCD     (1U << 23)  /* MDCR_EL2 */
-#define MDCR_EPMAD    (1U << 21)
-#define MDCR_EDAD     (1U << 20)
-#define MDCR_TTRF     (1U << 19)
-#define MDCR_STE      (1U << 18)  /* MDCR_EL3 */
-#define MDCR_SPME     (1U << 17)  /* MDCR_EL3 */
-#define MDCR_HPMD     (1U << 17)  /* MDCR_EL2 */
-#define MDCR_SDD      (1U << 16)
-#define MDCR_SPD      (3U << 14)
-#define MDCR_TDRA     (1U << 11)
-#define MDCR_TDOSA    (1U << 10)
-#define MDCR_TDA      (1U << 9)
-#define MDCR_TDE      (1U << 8)
-#define MDCR_HPME     (1U << 7)
-#define MDCR_TPM      (1U << 6)
-#define MDCR_TPMCR    (1U << 5)
-#define MDCR_HPMN     (0x1fU)
-
-/* Not all of the MDCR_EL3 bits are present in the 32-bit SDCR */
-#define SDCR_VALID_MASK (MDCR_MTPME | MDCR_TDCC | MDCR_SCCD | \
-                         MDCR_EPMAD | MDCR_EDAD | MDCR_TTRF | \
-                         MDCR_STE | MDCR_SPME | MDCR_SPD)
-
 #define CPSR_M (0x1fU)
 #define CPSR_T (1U << 5)
 #define CPSR_F (1U << 6)
@@ -1495,41 +1423,6 @@ FIELD(CPTR_EL3, TCPAC, 31, 1)
 #define XPSR_NZCV CPSR_NZCV
 #define XPSR_IT CPSR_IT
 
-#define TTBCR_N      (7U << 0) /* TTBCR.EAE==0 */
-#define TTBCR_T0SZ   (7U << 0) /* TTBCR.EAE==1 */
-#define TTBCR_PD0    (1U << 4)
-#define TTBCR_PD1    (1U << 5)
-#define TTBCR_EPD0   (1U << 7)
-#define TTBCR_IRGN0  (3U << 8)
-#define TTBCR_ORGN0  (3U << 10)
-#define TTBCR_SH0    (3U << 12)
-#define TTBCR_T1SZ   (3U << 16)
-#define TTBCR_A1     (1U << 22)
-#define TTBCR_EPD1   (1U << 23)
-#define TTBCR_IRGN1  (3U << 24)
-#define TTBCR_ORGN1  (3U << 26)
-#define TTBCR_SH1    (1U << 28)
-#define TTBCR_EAE    (1U << 31)
-
-FIELD(VTCR, T0SZ, 0, 6)
-FIELD(VTCR, SL0, 6, 2)
-FIELD(VTCR, IRGN0, 8, 2)
-FIELD(VTCR, ORGN0, 10, 2)
-FIELD(VTCR, SH0, 12, 2)
-FIELD(VTCR, TG0, 14, 2)
-FIELD(VTCR, PS, 16, 3)
-FIELD(VTCR, VS, 19, 1)
-FIELD(VTCR, HA, 21, 1)
-FIELD(VTCR, HD, 22, 1)
-FIELD(VTCR, HWU59, 25, 1)
-FIELD(VTCR, HWU60, 26, 1)
-FIELD(VTCR, HWU61, 27, 1)
-FIELD(VTCR, HWU62, 28, 1)
-FIELD(VTCR, NSW, 29, 1)
-FIELD(VTCR, NSA, 30, 1)
-FIELD(VTCR, DS, 32, 1)
-FIELD(VTCR, SL2, 33, 1)
-
 /* Bit definitions for ARMv8 SPSR (PSTATE) format.
  * Only these are valid when in AArch64 mode; in
  * AArch32 mode SPSRs are basically CPSR-format.
@@ -1737,21 +1630,6 @@ static inline void xpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
 #define HCR_TWEDEN    (1ULL << 59)
 #define HCR_TWEDEL    MAKE_64BIT_MASK(60, 4)
 
-#define HCRX_ENAS0    (1ULL << 0)
-#define HCRX_ENALS    (1ULL << 1)
-#define HCRX_ENASR    (1ULL << 2)
-#define HCRX_FNXS     (1ULL << 3)
-#define HCRX_FGTNXS   (1ULL << 4)
-#define HCRX_SMPME    (1ULL << 5)
-#define HCRX_TALLINT  (1ULL << 6)
-#define HCRX_VINMI    (1ULL << 7)
-#define HCRX_VFNMI    (1ULL << 8)
-#define HCRX_CMOW     (1ULL << 9)
-#define HCRX_MCE2     (1ULL << 10)
-#define HCRX_MSCEN    (1ULL << 11)
-
-#define HPFAR_NS      (1ULL << 63)
-
 #define SCR_NS                (1ULL << 0)
 #define SCR_IRQ               (1ULL << 1)
 #define SCR_FIQ               (1ULL << 2)
@@ -1790,12 +1668,6 @@ static inline void xpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
 #define SCR_GPF               (1ULL << 48)
 #define SCR_NSE               (1ULL << 62)
 
-#define HSTR_TTEE (1 << 16)
-#define HSTR_TJDBX (1 << 17)
-
-#define CNTHCTL_CNTVMASK      (1 << 18)
-#define CNTHCTL_CNTPMASK      (1 << 19)
-
 /* Return the current FPSCR value.  */
 uint32_t vfp_get_fpscr(CPUARMState *env);
 void vfp_set_fpscr(CPUARMState *env, uint32_t val);
diff --git a/target/arm/internals.h b/target/arm/internals.h
index 50bff445494..c93acb270cc 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -99,6 +99,134 @@ FIELD(DBGWCR, WT, 20, 1)
 FIELD(DBGWCR, MASK, 24, 5)
 FIELD(DBGWCR, SSCE, 29, 1)
 
+#define VTCR_NSW (1u << 29)
+#define VTCR_NSA (1u << 30)
+#define VSTCR_SW VTCR_NSW
+#define VSTCR_SA VTCR_NSA
+
+/* Bit definitions for CPACR (AArch32 only) */
+FIELD(CPACR, CP10, 20, 2)
+FIELD(CPACR, CP11, 22, 2)
+FIELD(CPACR, TRCDIS, 28, 1)    /* matches CPACR_EL1.TTA */
+FIELD(CPACR, D32DIS, 30, 1)    /* up to v7; RAZ in v8 */
+FIELD(CPACR, ASEDIS, 31, 1)
+
+/* Bit definitions for CPACR_EL1 (AArch64 only) */
+FIELD(CPACR_EL1, ZEN, 16, 2)
+FIELD(CPACR_EL1, FPEN, 20, 2)
+FIELD(CPACR_EL1, SMEN, 24, 2)
+FIELD(CPACR_EL1, TTA, 28, 1)   /* matches CPACR.TRCDIS */
+
+/* Bit definitions for HCPTR (AArch32 only) */
+FIELD(HCPTR, TCP10, 10, 1)
+FIELD(HCPTR, TCP11, 11, 1)
+FIELD(HCPTR, TASE, 15, 1)
+FIELD(HCPTR, TTA, 20, 1)
+FIELD(HCPTR, TAM, 30, 1)       /* matches CPTR_EL2.TAM */
+FIELD(HCPTR, TCPAC, 31, 1)     /* matches CPTR_EL2.TCPAC */
+
+/* Bit definitions for CPTR_EL2 (AArch64 only) */
+FIELD(CPTR_EL2, TZ, 8, 1)      /* !E2H */
+FIELD(CPTR_EL2, TFP, 10, 1)    /* !E2H, matches HCPTR.TCP10 */
+FIELD(CPTR_EL2, TSM, 12, 1)    /* !E2H */
+FIELD(CPTR_EL2, ZEN, 16, 2)    /* E2H */
+FIELD(CPTR_EL2, FPEN, 20, 2)   /* E2H */
+FIELD(CPTR_EL2, SMEN, 24, 2)   /* E2H */
+FIELD(CPTR_EL2, TTA, 28, 1)
+FIELD(CPTR_EL2, TAM, 30, 1)    /* matches HCPTR.TAM */
+FIELD(CPTR_EL2, TCPAC, 31, 1)  /* matches HCPTR.TCPAC */
+
+/* Bit definitions for CPTR_EL3 (AArch64 only) */
+FIELD(CPTR_EL3, EZ, 8, 1)
+FIELD(CPTR_EL3, TFP, 10, 1)
+FIELD(CPTR_EL3, ESM, 12, 1)
+FIELD(CPTR_EL3, TTA, 20, 1)
+FIELD(CPTR_EL3, TAM, 30, 1)
+FIELD(CPTR_EL3, TCPAC, 31, 1)
+
+#define MDCR_MTPME    (1U << 28)
+#define MDCR_TDCC     (1U << 27)
+#define MDCR_HLP      (1U << 26)  /* MDCR_EL2 */
+#define MDCR_SCCD     (1U << 23)  /* MDCR_EL3 */
+#define MDCR_HCCD     (1U << 23)  /* MDCR_EL2 */
+#define MDCR_EPMAD    (1U << 21)
+#define MDCR_EDAD     (1U << 20)
+#define MDCR_TTRF     (1U << 19)
+#define MDCR_STE      (1U << 18)  /* MDCR_EL3 */
+#define MDCR_SPME     (1U << 17)  /* MDCR_EL3 */
+#define MDCR_HPMD     (1U << 17)  /* MDCR_EL2 */
+#define MDCR_SDD      (1U << 16)
+#define MDCR_SPD      (3U << 14)
+#define MDCR_TDRA     (1U << 11)
+#define MDCR_TDOSA    (1U << 10)
+#define MDCR_TDA      (1U << 9)
+#define MDCR_TDE      (1U << 8)
+#define MDCR_HPME     (1U << 7)
+#define MDCR_TPM      (1U << 6)
+#define MDCR_TPMCR    (1U << 5)
+#define MDCR_HPMN     (0x1fU)
+
+/* Not all of the MDCR_EL3 bits are present in the 32-bit SDCR */
+#define SDCR_VALID_MASK (MDCR_MTPME | MDCR_TDCC | MDCR_SCCD | \
+                         MDCR_EPMAD | MDCR_EDAD | MDCR_TTRF | \
+                         MDCR_STE | MDCR_SPME | MDCR_SPD)
+
+#define TTBCR_N      (7U << 0) /* TTBCR.EAE==0 */
+#define TTBCR_T0SZ   (7U << 0) /* TTBCR.EAE==1 */
+#define TTBCR_PD0    (1U << 4)
+#define TTBCR_PD1    (1U << 5)
+#define TTBCR_EPD0   (1U << 7)
+#define TTBCR_IRGN0  (3U << 8)
+#define TTBCR_ORGN0  (3U << 10)
+#define TTBCR_SH0    (3U << 12)
+#define TTBCR_T1SZ   (3U << 16)
+#define TTBCR_A1     (1U << 22)
+#define TTBCR_EPD1   (1U << 23)
+#define TTBCR_IRGN1  (3U << 24)
+#define TTBCR_ORGN1  (3U << 26)
+#define TTBCR_SH1    (1U << 28)
+#define TTBCR_EAE    (1U << 31)
+
+FIELD(VTCR, T0SZ, 0, 6)
+FIELD(VTCR, SL0, 6, 2)
+FIELD(VTCR, IRGN0, 8, 2)
+FIELD(VTCR, ORGN0, 10, 2)
+FIELD(VTCR, SH0, 12, 2)
+FIELD(VTCR, TG0, 14, 2)
+FIELD(VTCR, PS, 16, 3)
+FIELD(VTCR, VS, 19, 1)
+FIELD(VTCR, HA, 21, 1)
+FIELD(VTCR, HD, 22, 1)
+FIELD(VTCR, HWU59, 25, 1)
+FIELD(VTCR, HWU60, 26, 1)
+FIELD(VTCR, HWU61, 27, 1)
+FIELD(VTCR, HWU62, 28, 1)
+FIELD(VTCR, NSW, 29, 1)
+FIELD(VTCR, NSA, 30, 1)
+FIELD(VTCR, DS, 32, 1)
+FIELD(VTCR, SL2, 33, 1)
+
+#define HCRX_ENAS0    (1ULL << 0)
+#define HCRX_ENALS    (1ULL << 1)
+#define HCRX_ENASR    (1ULL << 2)
+#define HCRX_FNXS     (1ULL << 3)
+#define HCRX_FGTNXS   (1ULL << 4)
+#define HCRX_SMPME    (1ULL << 5)
+#define HCRX_TALLINT  (1ULL << 6)
+#define HCRX_VINMI    (1ULL << 7)
+#define HCRX_VFNMI    (1ULL << 8)
+#define HCRX_CMOW     (1ULL << 9)
+#define HCRX_MCE2     (1ULL << 10)
+#define HCRX_MSCEN    (1ULL << 11)
+
+#define HPFAR_NS      (1ULL << 63)
+
+#define HSTR_TTEE (1 << 16)
+#define HSTR_TJDBX (1 << 17)
+
+#define CNTHCTL_CNTVMASK      (1 << 18)
+#define CNTHCTL_CNTPMASK      (1 << 19)
+
 /* We use a few fake FSR values for internal purposes in M profile.
  * M profile cores don't have A/R format FSRs, but currently our
  * get_phys_addr() code assumes A/R profile and reports failures via
-- 
2.34.1

Re: [PATCH 1/8] target/arm: Move some register related defines to internals.h

[Philippe Mathieu-Daudé]

On 1/3/24 19:32, Peter Maydell wrote:
> cpu.h has a lot of #defines relating to CPU register fields.
> Most of these aren't actually used outside target/arm code,
> so there's no point in cluttering up the cpu.h file with them.
> Move some easy ones to internals.h.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> I want to add some more CNTHCTL_* values, and don't really
> want to put more into cpu.h. There's obviously more that could
> be moved here, but I don't want to get into doing too much
> all at once. I pondered having a different file for these,
> but probably we'd end up pulling it in everywhere we do
> internals.h.

Yeah, have been there before :/

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

> ---
>   target/arm/cpu.h       | 128 -----------------------------------------
>   target/arm/internals.h | 128 +++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 128 insertions(+), 128 deletions(-)

Re: [PATCH 1/8] target/arm: Move some register related defines to internals.h

[Richard Henderson]

On 3/1/24 08:32, Peter Maydell wrote:
> cpu.h has a lot of #defines relating to CPU register fields.
> Most of these aren't actually used outside target/arm code,
> so there's no point in cluttering up the cpu.h file with them.
> Move some easy ones to internals.h.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
> I want to add some more CNTHCTL_* values, and don't really
> want to put more into cpu.h. There's obviously more that could
> be moved here, but I don't want to get into doing too much
> all at once. I pondered having a different file for these,
> but probably we'd end up pulling it in everywhere we do
> internals.h.
> ---
>   target/arm/cpu.h       | 128 -----------------------------------------
>   target/arm/internals.h | 128 +++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 128 insertions(+), 128 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

[PATCH 2/8] target/arm: Timer _EL02 registers UNDEF for E2H == 0

[Peter Maydell]

The timer _EL02 registers should UNDEF for invalid accesses from EL2
or EL3 when HCR_EL2.E2H == 0, not take a cp access trap.  We were
delivering the exception to EL2 with the wrong syndrome.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 90c4fb72ce4..978df6f2823 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6551,7 +6551,7 @@ static CPAccessResult e2h_access(CPUARMState *env, const ARMCPRegInfo *ri,
         return CP_ACCESS_OK;
     }
     if (!(arm_hcr_el2_eff(env) & HCR_E2H)) {
-        return CP_ACCESS_TRAP;
+        return CP_ACCESS_TRAP_UNCATEGORIZED;
     }
     return CP_ACCESS_OK;
 }
-- 
2.34.1

Re: [PATCH 2/8] target/arm: Timer _EL02 registers UNDEF for E2H == 0

[Richard Henderson]

On 3/1/24 08:32, Peter Maydell wrote:
> The timer _EL02 registers should UNDEF for invalid accesses from EL2
> or EL3 when HCR_EL2.E2H == 0, not take a cp access trap.  We were
> delivering the exception to EL2 with the wrong syndrome.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/arm/helper.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

[PATCH 3/8] target/arm: use FIELD macro for CNTHCTL bit definitions

[Peter Maydell]

We prefer the FIELD macro over ad-hoc #defines for register bits;
switch CNTHCTL to that style before we add any more bits.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/internals.h | 19 +++++++++++++++++--
 target/arm/helper.c    |  9 ++++-----
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/target/arm/internals.h b/target/arm/internals.h
index c93acb270cc..6553e414934 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -224,8 +224,23 @@ FIELD(VTCR, SL2, 33, 1)
 #define HSTR_TTEE (1 << 16)
 #define HSTR_TJDBX (1 << 17)
 
-#define CNTHCTL_CNTVMASK      (1 << 18)
-#define CNTHCTL_CNTPMASK      (1 << 19)
+FIELD(CNTHCTL, EL0PCTEN, 0, 1)
+FIELD(CNTHCTL, EL0VCTEN, 1, 1)
+FIELD(CNTHCTL, EVNTEN, 2, 1)
+FIELD(CNTHCTL, EVNTDIR, 3, 1)
+FIELD(CNTHCTL, EVNTI, 4, 4)
+FIELD(CNTHCTL, EL0VTEN, 8, 1)
+FIELD(CNTHCTL, EL0PTEN, 9, 1)
+FIELD(CNTHCTL, EL1PCTEN, 10, 1)
+FIELD(CNTHCTL, EL1PTEN, 11, 1)
+FIELD(CNTHCTL, ECV, 12, 1)
+FIELD(CNTHCTL, EL1TVT, 13, 1)
+FIELD(CNTHCTL, EL1TVCT, 14, 1)
+FIELD(CNTHCTL, EL1NVPCT, 15, 1)
+FIELD(CNTHCTL, EL1NVVCT, 16, 1)
+FIELD(CNTHCTL, EVNTIS, 17, 1)
+FIELD(CNTHCTL, CNTVMASK, 18, 1)
+FIELD(CNTHCTL, CNTPMASK, 19, 1)
 
 /* We use a few fake FSR values for internal purposes in M profile.
  * M profile cores don't have A/R format FSRs, but currently our
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 978df6f2823..1c82d12a883 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -2652,8 +2652,8 @@ static void gt_update_irq(ARMCPU *cpu, int timeridx)
      * It is RES0 in Secure and NonSecure state.
      */
     if ((ss == ARMSS_Root || ss == ARMSS_Realm) &&
-        ((timeridx == GTIMER_VIRT && (cnthctl & CNTHCTL_CNTVMASK)) ||
-         (timeridx == GTIMER_PHYS && (cnthctl & CNTHCTL_CNTPMASK)))) {
+        ((timeridx == GTIMER_VIRT && (cnthctl & R_CNTHCTL_CNTVMASK_MASK)) ||
+         (timeridx == GTIMER_PHYS && (cnthctl & R_CNTHCTL_CNTPMASK_MASK)))) {
         irqstate = 0;
     }
 
@@ -2968,12 +2968,11 @@ static void gt_cnthctl_write(CPUARMState *env, const ARMCPRegInfo *ri,
 {
     ARMCPU *cpu = env_archcpu(env);
     uint32_t oldval = env->cp15.cnthctl_el2;
-
     raw_write(env, ri, value);
 
-    if ((oldval ^ value) & CNTHCTL_CNTVMASK) {
+    if ((oldval ^ value) & R_CNTHCTL_CNTVMASK_MASK) {
         gt_update_irq(cpu, GTIMER_VIRT);
-    } else if ((oldval ^ value) & CNTHCTL_CNTPMASK) {
+    } else if ((oldval ^ value) & R_CNTHCTL_CNTPMASK_MASK) {
         gt_update_irq(cpu, GTIMER_PHYS);
     }
 }
-- 
2.34.1

Re: [PATCH 3/8] target/arm: use FIELD macro for CNTHCTL bit definitions

[Philippe Mathieu-Daudé]

On 1/3/24 19:32, Peter Maydell wrote:
> We prefer the FIELD macro over ad-hoc #defines for register bits;
> switch CNTHCTL to that style before we add any more bits.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   target/arm/internals.h | 19 +++++++++++++++++--
>   target/arm/helper.c    |  9 ++++-----
>   2 files changed, 21 insertions(+), 7 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH 3/8] target/arm: use FIELD macro for CNTHCTL bit definitions

[Richard Henderson]

On 3/1/24 08:32, Peter Maydell wrote:
> We prefer the FIELD macro over ad-hoc #defines for register bits;
> switch CNTHCTL to that style before we add any more bits.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/arm/internals.h | 19 +++++++++++++++++--
>   target/arm/helper.c    |  9 ++++-----
>   2 files changed, 21 insertions(+), 7 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

Re: [PATCH 3/8] target/arm: use FIELD macro for CNTHCTL bit definitions

[Richard Henderson]

On 3/1/24 08:32, Peter Maydell wrote:
> We prefer the FIELD macro over ad-hoc #defines for register bits;
> switch CNTHCTL to that style before we add any more bits.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   target/arm/internals.h | 19 +++++++++++++++++--
>   target/arm/helper.c    |  9 ++++-----
>   2 files changed, 21 insertions(+), 7 deletions(-)
> 
> diff --git a/target/arm/internals.h b/target/arm/internals.h
> index c93acb270cc..6553e414934 100644
> --- a/target/arm/internals.h
> +++ b/target/arm/internals.h
> @@ -224,8 +224,23 @@ FIELD(VTCR, SL2, 33, 1)
>   #define HSTR_TTEE (1 << 16)
>   #define HSTR_TJDBX (1 << 17)
>   
> -#define CNTHCTL_CNTVMASK      (1 << 18)
> -#define CNTHCTL_CNTPMASK      (1 << 19)
> +FIELD(CNTHCTL, EL0PCTEN, 0, 1)
> +FIELD(CNTHCTL, EL0VCTEN, 1, 1)
> +FIELD(CNTHCTL, EVNTEN, 2, 1)
> +FIELD(CNTHCTL, EVNTDIR, 3, 1)
...
> +FIELD(CNTHCTL, EL0VTEN, 8, 1)
> +FIELD(CNTHCTL, EL0PTEN, 9, 1)
> +FIELD(CNTHCTL, EL1PCTEN, 10, 1)
> +FIELD(CNTHCTL, EL1PTEN, 11, 1)

These bits change definition based on HCR_E2H, which I remembered when I got to patch 5, 
which adds code nearby the existing tests of these bits.

It might be confusing to only provide the E2H versions, without some extra suffix?


r~

Re: [PATCH 3/8] target/arm: use FIELD macro for CNTHCTL bit definitions

[Peter Maydell]

On Fri, 1 Mar 2024 at 21:19, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 3/1/24 08:32, Peter Maydell wrote:
> > We prefer the FIELD macro over ad-hoc #defines for register bits;
> > switch CNTHCTL to that style before we add any more bits.
> >
> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> > ---
> >   target/arm/internals.h | 19 +++++++++++++++++--
> >   target/arm/helper.c    |  9 ++++-----
> >   2 files changed, 21 insertions(+), 7 deletions(-)
> >
> > diff --git a/target/arm/internals.h b/target/arm/internals.h
> > index c93acb270cc..6553e414934 100644
> > --- a/target/arm/internals.h
> > +++ b/target/arm/internals.h
> > @@ -224,8 +224,23 @@ FIELD(VTCR, SL2, 33, 1)
> >   #define HSTR_TTEE (1 << 16)
> >   #define HSTR_TJDBX (1 << 17)
> >
> > -#define CNTHCTL_CNTVMASK      (1 << 18)
> > -#define CNTHCTL_CNTPMASK      (1 << 19)
> > +FIELD(CNTHCTL, EL0PCTEN, 0, 1)
> > +FIELD(CNTHCTL, EL0VCTEN, 1, 1)
> > +FIELD(CNTHCTL, EVNTEN, 2, 1)
> > +FIELD(CNTHCTL, EVNTDIR, 3, 1)
> ...
> > +FIELD(CNTHCTL, EL0VTEN, 8, 1)
> > +FIELD(CNTHCTL, EL0PTEN, 9, 1)
> > +FIELD(CNTHCTL, EL1PCTEN, 10, 1)
> > +FIELD(CNTHCTL, EL1PTEN, 11, 1)
>
> These bits change definition based on HCR_E2H, which I remembered when I got to patch 5,
> which adds code nearby the existing tests of these bits.
>
> It might be confusing to only provide the E2H versions, without some extra suffix?

Yeah, bits 8..11 are RES0 if E2H is 0; bits 3 and 2 are the same;
bits 0 and 1 change (to EL1PCTEN and EL1PCEN, so bit 0 when E2H is 0
has the same name as bit 10 when E2H is 1).

I don't see the need to suffix the bits that are only relevant in
one context and RES0 in the other, only the ones where the bit has
the same name but a different location, or where the same bit
number has two names. So:

+/*
+ * Depending on the value of HCR_EL2.E2H, bits 0 and 1
+ * have different bit definitions, and EL1PCTEN might be
+ * bit 0 or bit 10. We use _E2H1 and _E2H0 suffixes to
+ * disambiguate if necessary.
+ */
+FIELD(CNTHCTL, EL0PCTEN_E2H1, 0, 1)
+FIELD(CNTHCTL, EL0VCTEN_E2H1, 1, 1)
+FIELD(CNTHCTL, EL1PCTEN_E2H0, 0, 1)
+FIELD(CNTHCTL, EL1PCEN_E2H0, 1, 1)
+FIELD(CNTHCTL, EVNTEN, 2, 1)
+FIELD(CNTHCTL, EVNTDIR, 3, 1)
+FIELD(CNTHCTL, EVNTI, 4, 4)
+FIELD(CNTHCTL, EL0VTEN, 8, 1)
+FIELD(CNTHCTL, EL0PTEN, 9, 1)
+FIELD(CNTHCTL, EL1PCTEN_E2H1, 10, 1)
+FIELD(CNTHCTL, EL1PTEN, 11, 1)
+FIELD(CNTHCTL, ECV, 12, 1)
+FIELD(CNTHCTL, EL1TVT, 13, 1)
+FIELD(CNTHCTL, EL1TVCT, 14, 1)
+FIELD(CNTHCTL, EL1NVPCT, 15, 1)
+FIELD(CNTHCTL, EL1NVVCT, 16, 1)
+FIELD(CNTHCTL, EVNTIS, 17, 1)
+FIELD(CNTHCTL, CNTVMASK, 18, 1)
+FIELD(CNTHCTL, CNTPMASK, 19, 1)

(and updating the uses in following patches as needed) ?

thanks
-- PMM

Re: [PATCH 3/8] target/arm: use FIELD macro for CNTHCTL bit definitions

[Richard Henderson]

On 3/4/24 03:21, Peter Maydell wrote:
> On Fri, 1 Mar 2024 at 21:19, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> On 3/1/24 08:32, Peter Maydell wrote:
>>> We prefer the FIELD macro over ad-hoc #defines for register bits;
>>> switch CNTHCTL to that style before we add any more bits.
>>>
>>> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
>>> ---
>>>    target/arm/internals.h | 19 +++++++++++++++++--
>>>    target/arm/helper.c    |  9 ++++-----
>>>    2 files changed, 21 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/target/arm/internals.h b/target/arm/internals.h
>>> index c93acb270cc..6553e414934 100644
>>> --- a/target/arm/internals.h
>>> +++ b/target/arm/internals.h
>>> @@ -224,8 +224,23 @@ FIELD(VTCR, SL2, 33, 1)
>>>    #define HSTR_TTEE (1 << 16)
>>>    #define HSTR_TJDBX (1 << 17)
>>>
>>> -#define CNTHCTL_CNTVMASK      (1 << 18)
>>> -#define CNTHCTL_CNTPMASK      (1 << 19)
>>> +FIELD(CNTHCTL, EL0PCTEN, 0, 1)
>>> +FIELD(CNTHCTL, EL0VCTEN, 1, 1)
>>> +FIELD(CNTHCTL, EVNTEN, 2, 1)
>>> +FIELD(CNTHCTL, EVNTDIR, 3, 1)
>> ...
>>> +FIELD(CNTHCTL, EL0VTEN, 8, 1)
>>> +FIELD(CNTHCTL, EL0PTEN, 9, 1)
>>> +FIELD(CNTHCTL, EL1PCTEN, 10, 1)
>>> +FIELD(CNTHCTL, EL1PTEN, 11, 1)
>>
>> These bits change definition based on HCR_E2H, which I remembered when I got to patch 5,
>> which adds code nearby the existing tests of these bits.
>>
>> It might be confusing to only provide the E2H versions, without some extra suffix?
> 
> Yeah, bits 8..11 are RES0 if E2H is 0; bits 3 and 2 are the same;
> bits 0 and 1 change (to EL1PCTEN and EL1PCEN, so bit 0 when E2H is 0
> has the same name as bit 10 when E2H is 1).
> 
> I don't see the need to suffix the bits that are only relevant in
> one context and RES0 in the other, only the ones where the bit has
> the same name but a different location, or where the same bit
> number has two names. So:
> 
> +/*
> + * Depending on the value of HCR_EL2.E2H, bits 0 and 1
> + * have different bit definitions, and EL1PCTEN might be
> + * bit 0 or bit 10. We use _E2H1 and _E2H0 suffixes to
> + * disambiguate if necessary.
> + */
> +FIELD(CNTHCTL, EL0PCTEN_E2H1, 0, 1)
> +FIELD(CNTHCTL, EL0VCTEN_E2H1, 1, 1)
> +FIELD(CNTHCTL, EL1PCTEN_E2H0, 0, 1)
> +FIELD(CNTHCTL, EL1PCEN_E2H0, 1, 1)
> +FIELD(CNTHCTL, EVNTEN, 2, 1)
> +FIELD(CNTHCTL, EVNTDIR, 3, 1)
> +FIELD(CNTHCTL, EVNTI, 4, 4)
> +FIELD(CNTHCTL, EL0VTEN, 8, 1)
> +FIELD(CNTHCTL, EL0PTEN, 9, 1)
> +FIELD(CNTHCTL, EL1PCTEN_E2H1, 10, 1)
> +FIELD(CNTHCTL, EL1PTEN, 11, 1)
> +FIELD(CNTHCTL, ECV, 12, 1)
> +FIELD(CNTHCTL, EL1TVT, 13, 1)
> +FIELD(CNTHCTL, EL1TVCT, 14, 1)
> +FIELD(CNTHCTL, EL1NVPCT, 15, 1)
> +FIELD(CNTHCTL, EL1NVVCT, 16, 1)
> +FIELD(CNTHCTL, EVNTIS, 17, 1)
> +FIELD(CNTHCTL, CNTVMASK, 18, 1)
> +FIELD(CNTHCTL, CNTPMASK, 19, 1)
> 
> (and updating the uses in following patches as needed) ?

Looks good, thanks.


r~

[PATCH 4/8] target/arm: Don't allow RES0 CNTHCTL_EL2 bits to be written

[Peter Maydell]

Don't allow the guest to write CNTHCTL_EL2 bits which don't exist.
This is not strictly architecturally required, but it is how we've
tended to implement registers more recently.

In particular, bits [19:18] are only present with FEAT_RME,
and bits [17:12] will only be present with FEAT_ECV.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 1c82d12a883..8ec61c12440 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -2968,6 +2968,24 @@ static void gt_cnthctl_write(CPUARMState *env, const ARMCPRegInfo *ri,
 {
     ARMCPU *cpu = env_archcpu(env);
     uint32_t oldval = env->cp15.cnthctl_el2;
+    uint32_t valid_mask =
+        R_CNTHCTL_EL0PCTEN_MASK |
+        R_CNTHCTL_EL0VCTEN_MASK |
+        R_CNTHCTL_EVNTEN_MASK |
+        R_CNTHCTL_EVNTDIR_MASK |
+        R_CNTHCTL_EVNTI_MASK |
+        R_CNTHCTL_EL0VTEN_MASK |
+        R_CNTHCTL_EL0PTEN_MASK |
+        R_CNTHCTL_EL1PCTEN_MASK |
+        R_CNTHCTL_EL1PTEN_MASK;
+
+    if (cpu_isar_feature(aa64_rme, cpu)) {
+        valid_mask |= R_CNTHCTL_CNTVMASK_MASK | R_CNTHCTL_CNTPMASK_MASK;
+    }
+
+    /* Clear RES0 bits */
+    value &= valid_mask;
+
     raw_write(env, ri, value);
 
     if ((oldval ^ value) & R_CNTHCTL_CNTVMASK_MASK) {
-- 
2.34.1

Re: [PATCH 4/8] target/arm: Don't allow RES0 CNTHCTL_EL2 bits to be written

[Richard Henderson]

On 3/1/24 08:32, Peter Maydell wrote:
> Don't allow the guest to write CNTHCTL_EL2 bits which don't exist.
> This is not strictly architecturally required, but it is how we've
> tended to implement registers more recently.
> 
> In particular, bits [19:18] are only present with FEAT_RME,
> and bits [17:12] will only be present with FEAT_ECV.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/arm/helper.c | 18 ++++++++++++++++++
>   1 file changed, 18 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

[PATCH 5/8] target/arm: Implement new FEAT_ECV trap bits

[Peter Maydell]

The functionality defined by ID_AA64MMFR0_EL1.ECV == 1 is:
 * four new trap bits for various counter and timer registers
 * the CNTHCTL_EL2.EVNTIS and CNTKCTL_EL1.EVNTIS bits which control
   scaling of the event stream. This is a no-op for us, because we don't
   implement the event stream (our WFE is a NOP): all we need to do is
   allow CNTHCTL_EL2.ENVTIS to be read and written.
 * extensions to PMSCR_EL1.PCT, PMSCR_EL2.PCT, TRFCR_EL1.TS and
   TRFCR_EL2.TS: these are all no-ops for us, because we don't implement
   FEAT_SPE or FEAT_TRF.
 * new registers CNTPCTSS_EL0 and NCTVCTSS_EL0 which are
   "self-sychronizing" views of the CNTPCT_EL0 and CNTVCT_EL0, meaning
   that no barriers are needed around their accesses. For us these
   are just the same as the normal views, because all our sysregs are
   inherently self-sychronizing.

In this commit we implement the trap handling and permit the new
CNTHCTL_EL2 bits to be written.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/cpu-features.h |  5 ++++
 target/arm/helper.c       | 51 +++++++++++++++++++++++++++++++++++----
 2 files changed, 51 insertions(+), 5 deletions(-)

diff --git a/target/arm/cpu-features.h b/target/arm/cpu-features.h
index 7567854db63..b447ec5c0e6 100644
--- a/target/arm/cpu-features.h
+++ b/target/arm/cpu-features.h
@@ -741,6 +741,11 @@ static inline bool isar_feature_aa64_fgt(const ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64mmfr0, ID_AA64MMFR0, FGT) != 0;
 }
 
+static inline bool isar_feature_aa64_ecv_traps(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64mmfr0, ID_AA64MMFR0, ECV) > 0;
+}
+
 static inline bool isar_feature_aa64_vh(const ARMISARegisters *id)
 {
     return FIELD_EX64(id->id_aa64mmfr1, ID_AA64MMFR1, VH) != 0;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 8ec61c12440..6c528903a9a 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -2530,6 +2530,11 @@ static CPAccessResult gt_counter_access(CPUARMState *env, int timeridx,
              : !extract32(env->cp15.cnthctl_el2, 0, 1))) {
             return CP_ACCESS_TRAP_EL2;
         }
+        if (has_el2 && timeridx == GTIMER_VIRT) {
+            if (FIELD_EX64(env->cp15.cnthctl_el2, CNTHCTL, EL1TVCT)) {
+                return CP_ACCESS_TRAP_EL2;
+            }
+        }
         break;
     }
     return CP_ACCESS_OK;
@@ -2573,6 +2578,11 @@ static CPAccessResult gt_timer_access(CPUARMState *env, int timeridx,
                 }
             }
         }
+        if (has_el2 && timeridx == GTIMER_VIRT) {
+            if (FIELD_EX64(env->cp15.cnthctl_el2, CNTHCTL, EL1TVT)) {
+                return CP_ACCESS_TRAP_EL2;
+            }
+        }
         break;
     }
     return CP_ACCESS_OK;
@@ -2982,6 +2992,14 @@ static void gt_cnthctl_write(CPUARMState *env, const ARMCPRegInfo *ri,
     if (cpu_isar_feature(aa64_rme, cpu)) {
         valid_mask |= R_CNTHCTL_CNTVMASK_MASK | R_CNTHCTL_CNTPMASK_MASK;
     }
+    if (cpu_isar_feature(aa64_ecv_traps, cpu)) {
+        valid_mask |=
+            R_CNTHCTL_EL1TVT_MASK |
+            R_CNTHCTL_EL1TVCT_MASK |
+            R_CNTHCTL_EL1NVPCT_MASK |
+            R_CNTHCTL_EL1NVVCT_MASK |
+            R_CNTHCTL_EVNTIS_MASK;
+    }
 
     /* Clear RES0 bits */
     value &= valid_mask;
@@ -6564,7 +6582,6 @@ static CPAccessResult e2h_access(CPUARMState *env, const ARMCPRegInfo *ri,
 {
     if (arm_current_el(env) == 1) {
         /* This must be a FEAT_NV access */
-        /* TODO: FEAT_ECV will need to check CNTHCTL_EL2 here */
         return CP_ACCESS_OK;
     }
     if (!(arm_hcr_el2_eff(env) & HCR_E2H)) {
@@ -6573,6 +6590,30 @@ static CPAccessResult e2h_access(CPUARMState *env, const ARMCPRegInfo *ri,
     return CP_ACCESS_OK;
 }
 
+static CPAccessResult access_el1nvpct(CPUARMState *env, const ARMCPRegInfo *ri,
+                                      bool isread)
+{
+    if (arm_current_el(env) == 1) {
+        /* This must be a FEAT_NV access with NVx == 101 */
+        if (FIELD_EX64(env->cp15.cnthctl_el2, CNTHCTL, EL1NVPCT)) {
+            return CP_ACCESS_TRAP_EL2;
+        }
+    }
+    return e2h_access(env, ri, isread);
+}
+
+static CPAccessResult access_el1nvvct(CPUARMState *env, const ARMCPRegInfo *ri,
+                                      bool isread)
+{
+    if (arm_current_el(env) == 1) {
+        /* This must be a FEAT_NV access with NVx == 101 */
+        if (FIELD_EX64(env->cp15.cnthctl_el2, CNTHCTL, EL1NVVCT)) {
+            return CP_ACCESS_TRAP_EL2;
+        }
+    }
+    return e2h_access(env, ri, isread);
+}
+
 /* Test if system register redirection is to occur in the current state.  */
 static bool redirect_for_e2h(CPUARMState *env)
 {
@@ -8398,14 +8439,14 @@ static const ARMCPRegInfo vhe_reginfo[] = {
     { .name = "CNTP_CTL_EL02", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .opc1 = 5, .crn = 14, .crm = 2, .opc2 = 1,
       .type = ARM_CP_IO | ARM_CP_ALIAS,
-      .access = PL2_RW, .accessfn = e2h_access,
+      .access = PL2_RW, .accessfn = access_el1nvpct,
       .nv2_redirect_offset = 0x180 | NV2_REDIR_NO_NV1,
       .fieldoffset = offsetof(CPUARMState, cp15.c14_timer[GTIMER_PHYS].ctl),
       .writefn = gt_phys_ctl_write, .raw_writefn = raw_write },
     { .name = "CNTV_CTL_EL02", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .opc1 = 5, .crn = 14, .crm = 3, .opc2 = 1,
       .type = ARM_CP_IO | ARM_CP_ALIAS,
-      .access = PL2_RW, .accessfn = e2h_access,
+      .access = PL2_RW, .accessfn = access_el1nvvct,
       .nv2_redirect_offset = 0x170 | NV2_REDIR_NO_NV1,
       .fieldoffset = offsetof(CPUARMState, cp15.c14_timer[GTIMER_VIRT].ctl),
       .writefn = gt_virt_ctl_write, .raw_writefn = raw_write },
@@ -8424,14 +8465,14 @@ static const ARMCPRegInfo vhe_reginfo[] = {
       .type = ARM_CP_IO | ARM_CP_ALIAS,
       .fieldoffset = offsetof(CPUARMState, cp15.c14_timer[GTIMER_PHYS].cval),
       .nv2_redirect_offset = 0x178 | NV2_REDIR_NO_NV1,
-      .access = PL2_RW, .accessfn = e2h_access,
+      .access = PL2_RW, .accessfn = access_el1nvpct,
       .writefn = gt_phys_cval_write, .raw_writefn = raw_write },
     { .name = "CNTV_CVAL_EL02", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .opc1 = 5, .crn = 14, .crm = 3, .opc2 = 2,
       .type = ARM_CP_IO | ARM_CP_ALIAS,
       .nv2_redirect_offset = 0x168 | NV2_REDIR_NO_NV1,
       .fieldoffset = offsetof(CPUARMState, cp15.c14_timer[GTIMER_VIRT].cval),
-      .access = PL2_RW, .accessfn = e2h_access,
+      .access = PL2_RW, .accessfn = access_el1nvvct,
       .writefn = gt_virt_cval_write, .raw_writefn = raw_write },
 #endif
 };
-- 
2.34.1

Re: [PATCH 5/8] target/arm: Implement new FEAT_ECV trap bits

[Richard Henderson]

On 3/1/24 08:32, Peter Maydell wrote:
> The functionality defined by ID_AA64MMFR0_EL1.ECV == 1 is:
>   * four new trap bits for various counter and timer registers
>   * the CNTHCTL_EL2.EVNTIS and CNTKCTL_EL1.EVNTIS bits which control
>     scaling of the event stream. This is a no-op for us, because we don't
>     implement the event stream (our WFE is a NOP): all we need to do is
>     allow CNTHCTL_EL2.ENVTIS to be read and written.
>   * extensions to PMSCR_EL1.PCT, PMSCR_EL2.PCT, TRFCR_EL1.TS and
>     TRFCR_EL2.TS: these are all no-ops for us, because we don't implement
>     FEAT_SPE or FEAT_TRF.
>   * new registers CNTPCTSS_EL0 and NCTVCTSS_EL0 which are
>     "self-sychronizing" views of the CNTPCT_EL0 and CNTVCT_EL0, meaning
>     that no barriers are needed around their accesses. For us these
>     are just the same as the normal views, because all our sysregs are
>     inherently self-sychronizing.
> 
> In this commit we implement the trap handling and permit the new
> CNTHCTL_EL2 bits to be written.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/arm/cpu-features.h |  5 ++++
>   target/arm/helper.c       | 51 +++++++++++++++++++++++++++++++++++----
>   2 files changed, 51 insertions(+), 5 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

[PATCH 6/8] target/arm: Define CNTPCTSS_EL0 and CNTVCTSS_EL0

[Peter Maydell]

For FEAT_ECV, new registers CNTPCTSS_EL0 and CNTVCTSS_EL0 are
defined, which are "self-synchronized" views of the physical and
virtual counts as seen in the CNTPCT_EL0 and CNTVCT_EL0 registers
(meaning that no barriers are needed around accesses to them to
ensure that reads of them do not occur speculatively and out-of-order
with other instructions).

For QEMU, all our system registers are self-synchronized, so we can
simply copy the existing implementation of CNTPCT_EL0 and CNTVCT_EL0
to the new register encodings.

This means we now implement all the functionality required for
ID_AA64MMFR0_EL1.ECV == 0b0001.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 6c528903a9a..3441b14ba39 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -3389,6 +3389,34 @@ static const ARMCPRegInfo generic_timer_cp_reginfo[] = {
     },
 };
 
+/*
+ * FEAT_ECV adds extra views of CNTVCT_EL0 and CNTPCT_EL0 which
+ * are "self-synchronizing". For QEMU all sysregs are self-synchronizing,
+ * so our implementations here are identical to the normal registers.
+ */
+static const ARMCPRegInfo gen_timer_ecv_cp_reginfo[] = {
+    { .name = "CNTVCTSS", .cp = 15, .crm = 14, .opc1 = 9,
+      .access = PL0_R, .type = ARM_CP_64BIT | ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = gt_vct_access,
+      .readfn = gt_virt_cnt_read, .resetfn = arm_cp_reset_ignore,
+    },
+    { .name = "CNTVCTSS_EL0", .state = ARM_CP_STATE_AA64,
+      .opc0 = 3, .opc1 = 3, .crn = 14, .crm = 0, .opc2 = 6,
+      .access = PL0_R, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = gt_vct_access, .readfn = gt_virt_cnt_read,
+    },
+    { .name = "CNTPCTSS", .cp = 15, .crm = 14, .opc1 = 8,
+      .access = PL0_R, .type = ARM_CP_64BIT | ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = gt_pct_access,
+      .readfn = gt_cnt_read, .resetfn = arm_cp_reset_ignore,
+    },
+    { .name = "CNTPCTSS_EL0", .state = ARM_CP_STATE_AA64,
+      .opc0 = 3, .opc1 = 3, .crn = 14, .crm = 0, .opc2 = 5,
+      .access = PL0_R, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = gt_pct_access, .readfn = gt_cnt_read,
+    },
+};
+
 #else
 
 /*
@@ -3422,6 +3450,18 @@ static const ARMCPRegInfo generic_timer_cp_reginfo[] = {
     },
 };
 
+/*
+ * CNTVCTSS_EL0 has the same trap conditions as CNTVCT_EL0, so it also
+ * is exposed to userspace by Linux.
+ */
+static const ARMCPRegInfo gen_timer_ecv_cp_reginfo[] = {
+    { .name = "CNTVCTSS_EL0", .state = ARM_CP_STATE_AA64,
+      .opc0 = 3, .opc1 = 3, .crn = 14, .crm = 0, .opc2 = 6,
+      .access = PL0_R, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .readfn = gt_virt_cnt_read,
+    },
+};
+
 #endif
 
 static void par_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value)
@@ -9258,6 +9298,9 @@ void register_cp_regs_for_features(ARMCPU *cpu)
     if (arm_feature(env, ARM_FEATURE_GENERIC_TIMER)) {
         define_arm_cp_regs(cpu, generic_timer_cp_reginfo);
     }
+    if (cpu_isar_feature(aa64_ecv_traps, cpu)) {
+        define_arm_cp_regs(cpu, gen_timer_ecv_cp_reginfo);
+    }
     if (arm_feature(env, ARM_FEATURE_VAPA)) {
         ARMCPRegInfo vapa_cp_reginfo[] = {
             { .name = "PAR", .cp = 15, .crn = 7, .crm = 4, .opc1 = 0, .opc2 = 0,
-- 
2.34.1

Re: [PATCH 6/8] target/arm: Define CNTPCTSS_EL0 and CNTVCTSS_EL0

[Richard Henderson]

On 3/1/24 08:32, Peter Maydell wrote:
> For FEAT_ECV, new registers CNTPCTSS_EL0 and CNTVCTSS_EL0 are
> defined, which are "self-synchronized" views of the physical and
> virtual counts as seen in the CNTPCT_EL0 and CNTVCT_EL0 registers
> (meaning that no barriers are needed around accesses to them to
> ensure that reads of them do not occur speculatively and out-of-order
> with other instructions).
> 
> For QEMU, all our system registers are self-synchronized, so we can
> simply copy the existing implementation of CNTPCT_EL0 and CNTVCT_EL0
> to the new register encodings.
> 
> This means we now implement all the functionality required for
> ID_AA64MMFR0_EL1.ECV == 0b0001.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/arm/helper.c | 43 +++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 43 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

[PATCH 7/8] target/arm: Implement FEAT_ECV CNTPOFF_EL2 handling

[Peter Maydell]

When ID_AA64MMFR0_EL1.ECV is 0b0010, a new register CNTPOFF_EL2 is
implemented.  This is similar to the existing CNTVOFF_EL2, except
that it controls a hypervisor-adjustable offset made to the physical
counter and timer.

Implement the handling for this register, which includes control/trap
bits in SCR_EL3 and CNTHCTL_EL2.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/cpu-features.h |  5 +++
 target/arm/cpu.h          |  1 +
 target/arm/helper.c       | 68 +++++++++++++++++++++++++++++++++++++--
 target/arm/trace-events   |  1 +
 4 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/target/arm/cpu-features.h b/target/arm/cpu-features.h
index b447ec5c0e6..e5758d9fbc8 100644
--- a/target/arm/cpu-features.h
+++ b/target/arm/cpu-features.h
@@ -746,6 +746,11 @@ static inline bool isar_feature_aa64_ecv_traps(const ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64mmfr0, ID_AA64MMFR0, ECV) > 0;
 }
 
+static inline bool isar_feature_aa64_ecv(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64mmfr0, ID_AA64MMFR0, ECV) > 1;
+}
+
 static inline bool isar_feature_aa64_vh(const ARMISARegisters *id)
 {
     return FIELD_EX64(id->id_aa64mmfr1, ID_AA64MMFR1, VH) != 0;
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 3cbfd4f9a74..262ebbf1c19 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -453,6 +453,7 @@ typedef struct CPUArchState {
         uint64_t c14_cntkctl; /* Timer Control register */
         uint64_t cnthctl_el2; /* Counter/Timer Hyp Control register */
         uint64_t cntvoff_el2; /* Counter Virtual Offset register */
+        uint64_t cntpoff_el2; /* Counter Physical Offset register */
         ARMGenericTimer c14_timer[NUM_GTIMERS];
         uint32_t c15_cpar; /* XScale Coprocessor Access Register */
         uint32_t c15_ticonfig; /* TI925T configuration byte.  */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 3441b14ba39..f590bdf0f7e 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1923,6 +1923,9 @@ static void scr_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value)
         if (cpu_isar_feature(aa64_rme, cpu)) {
             valid_mask |= SCR_NSE | SCR_GPF;
         }
+        if (cpu_isar_feature(aa64_ecv, cpu)) {
+            valid_mask |= SCR_ECVEN;
+        }
     } else {
         valid_mask &= ~(SCR_RW | SCR_ST);
         if (cpu_isar_feature(aa32_ras, cpu)) {
@@ -2682,6 +2685,25 @@ void gt_rme_post_el_change(ARMCPU *cpu, void *ignored)
     gt_update_irq(cpu, GTIMER_PHYS);
 }
 
+static uint64_t gt_phys_raw_cnt_offset(CPUARMState *env)
+{
+    if ((env->cp15.scr_el3 & SCR_ECVEN) &&
+        FIELD_EX64(env->cp15.cnthctl_el2, CNTHCTL, ECV) &&
+        arm_is_el2_enabled(env) &&
+        (arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE)) {
+        return env->cp15.cntpoff_el2;
+    }
+    return 0;
+}
+
+static uint64_t gt_phys_cnt_offset(CPUARMState *env)
+{
+    if (arm_current_el(env) >= 2) {
+        return 0;
+    }
+    return gt_phys_raw_cnt_offset(env);
+}
+
 static void gt_recalc_timer(ARMCPU *cpu, int timeridx)
 {
     ARMGenericTimer *gt = &cpu->env.cp15.c14_timer[timeridx];
@@ -2692,7 +2714,7 @@ static void gt_recalc_timer(ARMCPU *cpu, int timeridx)
          * reset timer to when ISTATUS next has to change
          */
         uint64_t offset = timeridx == GTIMER_VIRT ?
-                                      cpu->env.cp15.cntvoff_el2 : 0;
+            cpu->env.cp15.cntvoff_el2 : gt_phys_raw_cnt_offset(&cpu->env);
         uint64_t count = gt_get_countervalue(&cpu->env);
         /* Note that this must be unsigned 64 bit arithmetic: */
         int istatus = count - offset >= gt->cval;
@@ -2755,7 +2777,7 @@ static void gt_timer_reset(CPUARMState *env, const ARMCPRegInfo *ri,
 
 static uint64_t gt_cnt_read(CPUARMState *env, const ARMCPRegInfo *ri)
 {
-    return gt_get_countervalue(env);
+    return gt_get_countervalue(env) - gt_phys_cnt_offset(env);
 }
 
 static uint64_t gt_virt_cnt_offset(CPUARMState *env)
@@ -2804,6 +2826,9 @@ static uint64_t gt_tval_read(CPUARMState *env, const ARMCPRegInfo *ri,
     case GTIMER_HYPVIRT:
         offset = gt_virt_cnt_offset(env);
         break;
+    case GTIMER_PHYS:
+        offset = gt_phys_cnt_offset(env);
+        break;
     }
 
     return (uint32_t)(env->cp15.c14_timer[timeridx].cval -
@@ -2821,6 +2846,9 @@ static void gt_tval_write(CPUARMState *env, const ARMCPRegInfo *ri,
     case GTIMER_HYPVIRT:
         offset = gt_virt_cnt_offset(env);
         break;
+    case GTIMER_PHYS:
+        offset = gt_phys_cnt_offset(env);
+        break;
     }
 
     trace_arm_gt_tval_write(timeridx, value);
@@ -3000,6 +3028,9 @@ static void gt_cnthctl_write(CPUARMState *env, const ARMCPRegInfo *ri,
             R_CNTHCTL_EL1NVVCT_MASK |
             R_CNTHCTL_EVNTIS_MASK;
     }
+    if (cpu_isar_feature(aa64_ecv, cpu)) {
+        valid_mask |= R_CNTHCTL_ECV_MASK;
+    }
 
     /* Clear RES0 bits */
     value &= valid_mask;
@@ -3417,6 +3448,34 @@ static const ARMCPRegInfo gen_timer_ecv_cp_reginfo[] = {
     },
 };
 
+static CPAccessResult gt_cntpoff_access(CPUARMState *env,
+                                        const ARMCPRegInfo *ri,
+                                        bool isread)
+{
+    if (arm_current_el(env) == 2 && !(env->cp15.scr_el3 & SCR_ECVEN)) {
+        return CP_ACCESS_TRAP_EL3;
+    }
+    return CP_ACCESS_OK;
+}
+
+static void gt_cntpoff_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                              uint64_t value)
+{
+    ARMCPU *cpu = env_archcpu(env);
+
+    trace_arm_gt_cntpoff_write(value);
+    raw_write(env, ri, value);
+    gt_recalc_timer(cpu, GTIMER_PHYS);
+}
+
+static const ARMCPRegInfo gen_timer_cntpoff_reginfo = {
+    .name = "CNTPOFF_EL2", .state = ARM_CP_STATE_AA64,
+    .opc0 = 3, .opc1 = 4, .crn = 14, .crm = 0, .opc2 = 6,
+    .access = PL2_RW, .type = ARM_CP_IO, .resetvalue = 0,
+    .accessfn = gt_cntpoff_access, .writefn = gt_cntpoff_write,
+    .nv2_redirect_offset = 0x1a8,
+    .fieldoffset = offsetof(CPUARMState, cp15.cntpoff_el2),
+};
 #else
 
 /*
@@ -9301,6 +9360,11 @@ void register_cp_regs_for_features(ARMCPU *cpu)
     if (cpu_isar_feature(aa64_ecv_traps, cpu)) {
         define_arm_cp_regs(cpu, gen_timer_ecv_cp_reginfo);
     }
+#ifndef CONFIG_USER_ONLY
+    if (cpu_isar_feature(aa64_ecv, cpu)) {
+        define_one_arm_cp_reg(cpu, &gen_timer_cntpoff_reginfo);
+    }
+#endif
     if (arm_feature(env, ARM_FEATURE_VAPA)) {
         ARMCPRegInfo vapa_cp_reginfo[] = {
             { .name = "PAR", .cp = 15, .crn = 7, .crm = 4, .opc1 = 0, .opc2 = 0,
diff --git a/target/arm/trace-events b/target/arm/trace-events
index 48cc0512dbe..4438dce7bec 100644
--- a/target/arm/trace-events
+++ b/target/arm/trace-events
@@ -8,6 +8,7 @@ arm_gt_tval_write(int timer, uint64_t value) "gt_tval_write: timer %d value 0x%"
 arm_gt_ctl_write(int timer, uint64_t value) "gt_ctl_write: timer %d value 0x%" PRIx64
 arm_gt_imask_toggle(int timer) "gt_ctl_write: timer %d IMASK toggle"
 arm_gt_cntvoff_write(uint64_t value) "gt_cntvoff_write: value 0x%" PRIx64
+arm_gt_cntpoff_write(uint64_t value) "gt_cntpoff_write: value 0x%" PRIx64
 arm_gt_update_irq(int timer, int irqstate) "gt_update_irq: timer %d irqstate %d"
 
 # kvm.c
-- 
2.34.1

Re: [PATCH 7/8] target/arm: Implement FEAT_ECV CNTPOFF_EL2 handling

[Richard Henderson]

On 3/1/24 08:32, Peter Maydell wrote:
> +static uint64_t gt_phys_raw_cnt_offset(CPUARMState *env)
> +{
> +    if ((env->cp15.scr_el3 & SCR_ECVEN) &&
> +        FIELD_EX64(env->cp15.cnthctl_el2, CNTHCTL, ECV) &&
> +        arm_is_el2_enabled(env) &&
> +        (arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE)) {

arm_hcr_el2_eff checks arm_is_el2_enabled and returns 0 if disabled.

Anyway,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~

Re: [PATCH 7/8] target/arm: Implement FEAT_ECV CNTPOFF_EL2 handling

[Peter Maydell]

On Fri, 1 Mar 2024 at 21:54, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 3/1/24 08:32, Peter Maydell wrote:
> > +static uint64_t gt_phys_raw_cnt_offset(CPUARMState *env)
> > +{
> > +    if ((env->cp15.scr_el3 & SCR_ECVEN) &&
> > +        FIELD_EX64(env->cp15.cnthctl_el2, CNTHCTL, ECV) &&
> > +        arm_is_el2_enabled(env) &&
> > +        (arm_hcr_el2_eff(env) & (HCR_E2H | HCR_TGE)) != (HCR_E2H | HCR_TGE)) {
>
> arm_hcr_el2_eff checks arm_is_el2_enabled and returns 0 if disabled.

Yes, and if it returns 0 then the E2H|TGE bits will not be E2H|TGE,
and so we'll incorrectly apply the CNTPOFF value. We can only elide
the arm_is_el2_enabled() test if we're checking for some HCR bit
being 1. (I also initially thought the arm_is_el2_enabled() check was
redundant and then found it was not :-))

-- PMM

[PATCH 8/8] target/arm: Enable FEAT_ECV for 'max' CPU

[Peter Maydell]

Enable all FEAT_ECV features on the 'max' CPU.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 docs/system/arm/emulation.rst | 1 +
 target/arm/tcg/cpu64.c        | 1 +
 2 files changed, 2 insertions(+)

diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
index f67aea2d836..2a7bbb82dc4 100644
--- a/docs/system/arm/emulation.rst
+++ b/docs/system/arm/emulation.rst
@@ -28,6 +28,7 @@ the following architecture extensions:
 - FEAT_DotProd (Advanced SIMD dot product instructions)
 - FEAT_DoubleFault (Double Fault Extension)
 - FEAT_E0PD (Preventing EL0 access to halves of address maps)
+- FEAT_ECV (Enhanced Counter Virtualization)
 - FEAT_EPAC (Enhanced pointer authentication)
 - FEAT_ETS (Enhanced Translation Synchronization)
 - FEAT_EVT (Enhanced Virtualization Traps)
diff --git a/target/arm/tcg/cpu64.c b/target/arm/tcg/cpu64.c
index 5fba2c0f040..9f7a9f3d2cc 100644
--- a/target/arm/tcg/cpu64.c
+++ b/target/arm/tcg/cpu64.c
@@ -1184,6 +1184,7 @@ void aarch64_max_tcg_initfn(Object *obj)
     t = FIELD_DP64(t, ID_AA64MMFR0, TGRAN64_2, 2); /* 64k stage2 supported */
     t = FIELD_DP64(t, ID_AA64MMFR0, TGRAN4_2, 2);  /*  4k stage2 supported */
     t = FIELD_DP64(t, ID_AA64MMFR0, FGT, 1);       /* FEAT_FGT */
+    t = FIELD_DP64(t, ID_AA64MMFR0, ECV, 2);       /* FEAT_ECV */
     cpu->isar.id_aa64mmfr0 = t;
 
     t = cpu->isar.id_aa64mmfr1;
-- 
2.34.1

Re: [PATCH 8/8] target/arm: Enable FEAT_ECV for 'max' CPU

[Philippe Mathieu-Daudé]

On 1/3/24 19:32, Peter Maydell wrote:
> Enable all FEAT_ECV features on the 'max' CPU.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   docs/system/arm/emulation.rst | 1 +
>   target/arm/tcg/cpu64.c        | 1 +
>   2 files changed, 2 insertions(+)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH 8/8] target/arm: Enable FEAT_ECV for 'max' CPU

[Richard Henderson]

On 3/1/24 08:32, Peter Maydell wrote:
> Enable all FEAT_ECV features on the 'max' CPU.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   docs/system/arm/emulation.rst | 1 +
>   target/arm/tcg/cpu64.c        | 1 +
>   2 files changed, 2 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~