[PATCH V2 0/7] arm64/hw_breakpoint: Enable FEAT_Debugv8p9

Anshuman Khandual posted 7 patches 1 year, 3 months ago
There is a newer version of this series
Documentation/arch/arm64/booting.rst    | 19 +++++++
arch/arm64/include/asm/debug-monitors.h |  1 +
arch/arm64/include/asm/el2_setup.h      | 26 +++++++++
arch/arm64/include/asm/hw_breakpoint.h  | 46 ++++++++++++----
arch/arm64/include/asm/kvm_arm.h        |  1 +
arch/arm64/kernel/cpufeature.c          | 21 ++++++--
arch/arm64/kernel/debug-monitors.c      | 15 ++++--
arch/arm64/kernel/hw_breakpoint.c       | 38 +++++++++++++-
arch/arm64/tools/sysreg                 | 70 +++++++++++++++++++++++++
9 files changed, 216 insertions(+), 21 deletions(-)
[PATCH V2 0/7] arm64/hw_breakpoint: Enable FEAT_Debugv8p9
Posted by Anshuman Khandual 1 year, 3 months ago
This series enables FEAT_Debugv8p9 thus extending breakpoint and watchpoint
support upto 64. This series is based on v6.12-rc5 although this depends on
FEAT_FGT2 FGU series posted earlier, for MDSELR_EL1 handling in various KVM
guest configurations.

https://lore.kernel.org/all/20241001024356.1096072-1-anshuman.khandual@arm.com/

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.linux.dev
Cc: linux-kernel@vger.kernel.org

Changes in V2:

Following changes have been made per review comments from Mark Rutland

- Orr MDCR_EL2_EBWE directly without an intermittent register
- Alphabetically order header files in debug-monitors.c
- Dropped embwe_ref_count mechanism
- Dropped preempt_enable() from AARCH64_DBG_READ
- Dropped preempt_disable() from AARCH64_DBG_WRITE
- Dropped set_bank_index()
- Renamed read/write_wb_reg() as __read/__write_wb_reg()
- Modified read/write_wb_reg() to have MDSELR_E1 based banked read/write
- Added required sysreg tools patches from KVM FEAT_FGT2 series for build

Changes in V1:

https://lore.kernel.org/all/20241001043602.1116991-1-anshuman.khandual@arm.com/

- Changed FTR_STRICT to FTR_NONSTRICT for the following ID_AA64DFR1_EL1
  register fields - ABL_CMPs, DPFZS, PMICNTR, CTX_CMPs, WRPs and BRPs

Changes in RFC V2:

https://lore.kernel.org/linux-arm-kernel/20240620092607.267132-1-anshuman.khandual@arm.com/

- This series has been split from RFC V1 dealing only with arm64 breakpoints
- Restored back DBG_MDSCR_MASK definition (unrelated change)
- Added preempt_disable()/enable() blocks between selecting banks and registers

Changes in RFC:

https://lore.kernel.org/all/20240405080008.1225223-1-anshuman.khandual@arm.com/

Anshuman Khandual (7):
  arm64/sysreg: Update register fields for ID_AA64MMFR0_EL1
  arm64/sysreg: Add register fields for MDSELR_EL1
  arm64/sysreg: Add register fields for HDFGRTR2_EL2
  arm64/sysreg: Add register fields for HDFGWTR2_EL2
  arm64/cpufeature: Add field details for ID_AA64DFR1_EL1 register
  arm64/boot: Enable EL2 requirements for FEAT_Debugv8p9
  arm64/hw_breakpoint: Enable FEAT_Debugv8p9

 Documentation/arch/arm64/booting.rst    | 19 +++++++
 arch/arm64/include/asm/debug-monitors.h |  1 +
 arch/arm64/include/asm/el2_setup.h      | 26 +++++++++
 arch/arm64/include/asm/hw_breakpoint.h  | 46 ++++++++++++----
 arch/arm64/include/asm/kvm_arm.h        |  1 +
 arch/arm64/kernel/cpufeature.c          | 21 ++++++--
 arch/arm64/kernel/debug-monitors.c      | 15 ++++--
 arch/arm64/kernel/hw_breakpoint.c       | 38 +++++++++++++-
 arch/arm64/tools/sysreg                 | 70 +++++++++++++++++++++++++
 9 files changed, 216 insertions(+), 21 deletions(-)

-- 
2.25.1
Re: [PATCH V2 0/7] arm64/hw_breakpoint: Enable FEAT_Debugv8p9
Posted by Mark Rutland 1 year, 1 month ago
On Mon, Oct 28, 2024 at 11:04:19AM +0530, Anshuman Khandual wrote:
> This series enables FEAT_Debugv8p9 thus extending breakpoint and watchpoint
> support upto 64. This series is based on v6.12-rc5 although this depends on
> FEAT_FGT2 FGU series posted earlier, for MDSELR_EL1 handling in various KVM
> guest configurations.
> 
> https://lore.kernel.org/all/20241001024356.1096072-1-anshuman.khandual@arm.com/

To avoid further confusion: since we discussed things further on the v1
thread after this v2 thread was posted, I'm waiting for a v3 to be
posted which addresses the comments there (e.g. ID reg field handling,
mutual exclusion for breakpoint manipulation).

Mark.

> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Oliver Upton <oliver.upton@linux.dev>
> Cc: James Morse <james.morse@arm.com>
> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Mark Brown <broonie@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: kvmarm@lists.linux.dev
> Cc: linux-kernel@vger.kernel.org
> 
> Changes in V2:
> 
> Following changes have been made per review comments from Mark Rutland
> 
> - Orr MDCR_EL2_EBWE directly without an intermittent register
> - Alphabetically order header files in debug-monitors.c
> - Dropped embwe_ref_count mechanism
> - Dropped preempt_enable() from AARCH64_DBG_READ
> - Dropped preempt_disable() from AARCH64_DBG_WRITE
> - Dropped set_bank_index()
> - Renamed read/write_wb_reg() as __read/__write_wb_reg()
> - Modified read/write_wb_reg() to have MDSELR_E1 based banked read/write
> - Added required sysreg tools patches from KVM FEAT_FGT2 series for build
> 
> Changes in V1:
> 
> https://lore.kernel.org/all/20241001043602.1116991-1-anshuman.khandual@arm.com/
> 
> - Changed FTR_STRICT to FTR_NONSTRICT for the following ID_AA64DFR1_EL1
>   register fields - ABL_CMPs, DPFZS, PMICNTR, CTX_CMPs, WRPs and BRPs
> 
> Changes in RFC V2:
> 
> https://lore.kernel.org/linux-arm-kernel/20240620092607.267132-1-anshuman.khandual@arm.com/
> 
> - This series has been split from RFC V1 dealing only with arm64 breakpoints
> - Restored back DBG_MDSCR_MASK definition (unrelated change)
> - Added preempt_disable()/enable() blocks between selecting banks and registers
> 
> Changes in RFC:
> 
> https://lore.kernel.org/all/20240405080008.1225223-1-anshuman.khandual@arm.com/
> 
> Anshuman Khandual (7):
>   arm64/sysreg: Update register fields for ID_AA64MMFR0_EL1
>   arm64/sysreg: Add register fields for MDSELR_EL1
>   arm64/sysreg: Add register fields for HDFGRTR2_EL2
>   arm64/sysreg: Add register fields for HDFGWTR2_EL2
>   arm64/cpufeature: Add field details for ID_AA64DFR1_EL1 register
>   arm64/boot: Enable EL2 requirements for FEAT_Debugv8p9
>   arm64/hw_breakpoint: Enable FEAT_Debugv8p9
> 
>  Documentation/arch/arm64/booting.rst    | 19 +++++++
>  arch/arm64/include/asm/debug-monitors.h |  1 +
>  arch/arm64/include/asm/el2_setup.h      | 26 +++++++++
>  arch/arm64/include/asm/hw_breakpoint.h  | 46 ++++++++++++----
>  arch/arm64/include/asm/kvm_arm.h        |  1 +
>  arch/arm64/kernel/cpufeature.c          | 21 ++++++--
>  arch/arm64/kernel/debug-monitors.c      | 15 ++++--
>  arch/arm64/kernel/hw_breakpoint.c       | 38 +++++++++++++-
>  arch/arm64/tools/sysreg                 | 70 +++++++++++++++++++++++++
>  9 files changed, 216 insertions(+), 21 deletions(-)
> 
> -- 
> 2.25.1
>
Re: [PATCH V2 0/7] arm64/hw_breakpoint: Enable FEAT_Debugv8p9
Posted by Anshuman Khandual 1 year, 1 month ago

On 12/10/24 22:29, Mark Rutland wrote:
> On Mon, Oct 28, 2024 at 11:04:19AM +0530, Anshuman Khandual wrote:
>> This series enables FEAT_Debugv8p9 thus extending breakpoint and watchpoint
>> support upto 64. This series is based on v6.12-rc5 although this depends on
>> FEAT_FGT2 FGU series posted earlier, for MDSELR_EL1 handling in various KVM
>> guest configurations.
>>
>> https://lore.kernel.org/all/20241001024356.1096072-1-anshuman.khandual@arm.com/
> To avoid further confusion: since we discussed things further on the v1
> thread after this v2 thread was posted, I'm waiting for a v3 to be
> posted which addresses the comments there (e.g. ID reg field handling,
> mutual exclusion for breakpoint manipulation).

Agreed, although I am still working on the mutual exclusion for breakpoint
manipulation problem. Besides just carved out - MDCR_EL3.[TDS|TPM] related
EL3 boot requirement's document update in a separate series as discussed.

https://lore.kernel.org/all/20241211065425.1106683-1-anshuman.khandual@arm.com/