Re: [PATCH v2 1/2] arch/powerpc/kvm: Add DPDES support in helper library for Guest state buffer

[Nicholas Piggin]

On Wed Jun 5, 2024 at 9:39 PM AEST, Gautam Menghani wrote:
> Add support for using DPDES in the library for using guest state
> buffers. DPDES support is needed for enabling usage of doorbells in a 
> L2 KVM on PAPR guest.
>

Reviewed-by: Nicholas Piggin <npiggin@xxxxxxxxx>

> Fixes: 6ccbbc33f06a ("KVM: PPC: Add helper library for Guest State Buffers")
> Cc: stable@xxxxxxxxxxxxxxx # v6.7
> Signed-off-by: Gautam Menghani <gautam@xxxxxxxxxxxxx>
> ---
>  Documentation/arch/powerpc/kvm-nested.rst     | 4 +++-
>  arch/powerpc/include/asm/guest-state-buffer.h | 3 ++-
>  arch/powerpc/include/asm/kvm_book3s.h         | 1 +
>  arch/powerpc/kvm/book3s_hv_nestedv2.c         | 7 +++++++
>  arch/powerpc/kvm/test-guest-state-buffer.c    | 2 +-
>  5 files changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/arch/powerpc/kvm-nested.rst b/Documentation/arch/powerpc/kvm-nested.rst
> index 630602a8aa00..5defd13cc6c1 100644
> --- a/Documentation/arch/powerpc/kvm-nested.rst
> +++ b/Documentation/arch/powerpc/kvm-nested.rst
> @@ -546,7 +546,9 @@ table information.
>  +--------+-------+----+--------+----------------------------------+
>  | 0x1052 | 0x08  | RW |   T    | CTRL                             |
>  +--------+-------+----+--------+----------------------------------+
> -| 0x1053-|       |    |        | Reserved                         |
> +| 0x1053 | 0x08  | RW |   T    | DPDES                            |
> ++--------+-------+----+--------+----------------------------------+
> +| 0x1054-|       |    |        | Reserved                         |
>  | 0x1FFF |       |    |        |                                  |
>  +--------+-------+----+--------+----------------------------------+
>  | 0x2000 | 0x04  | RW |   T    | CR                               |
> diff --git a/arch/powerpc/include/asm/guest-state-buffer.h b/arch/powerpc/include/asm/guest-state-buffer.h
> index 808149f31576..d107abe1468f 100644
> --- a/arch/powerpc/include/asm/guest-state-buffer.h
> +++ b/arch/powerpc/include/asm/guest-state-buffer.h
> @@ -81,6 +81,7 @@
>  #define KVMPPC_GSID_HASHKEYR			0x1050
>  #define KVMPPC_GSID_HASHPKEYR			0x1051
>  #define KVMPPC_GSID_CTRL			0x1052
> +#define KVMPPC_GSID_DPDES			0x1053
>  
>  #define KVMPPC_GSID_CR				0x2000
>  #define KVMPPC_GSID_PIDR			0x2001
> @@ -110,7 +111,7 @@
>  #define KVMPPC_GSE_META_COUNT (KVMPPC_GSE_META_END - KVMPPC_GSE_META_START + 1)
>  
>  #define KVMPPC_GSE_DW_REGS_START KVMPPC_GSID_GPR(0)
> -#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_CTRL
> +#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_DPDES
>  #define KVMPPC_GSE_DW_REGS_COUNT \
>  	(KVMPPC_GSE_DW_REGS_END - KVMPPC_GSE_DW_REGS_START + 1)
>  
> diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
> index 3e1e2a698c9e..10618622d7ef 100644
> --- a/arch/powerpc/include/asm/kvm_book3s.h
> +++ b/arch/powerpc/include/asm/kvm_book3s.h
> @@ -594,6 +594,7 @@ static inline u##size kvmppc_get_##reg(struct kvm_vcpu *vcpu)		\
>  
>  
>  KVMPPC_BOOK3S_VCORE_ACCESSOR(vtb, 64, KVMPPC_GSID_VTB)
> +KVMPPC_BOOK3S_VCORE_ACCESSOR(dpdes, 64, KVMPPC_GSID_DPDES)
>  KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(arch_compat, 32, KVMPPC_GSID_LOGICAL_PVR)
>  KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(lpcr, 64, KVMPPC_GSID_LPCR)
>  KVMPPC_BOOK3S_VCORE_ACCESSOR_SET(tb_offset, 64, KVMPPC_GSID_TB_OFFSET)
> diff --git a/arch/powerpc/kvm/book3s_hv_nestedv2.c b/arch/powerpc/kvm/book3s_hv_nestedv2.c
> index 8e6f5355f08b..36863fff2a99 100644
> --- a/arch/powerpc/kvm/book3s_hv_nestedv2.c
> +++ b/arch/powerpc/kvm/book3s_hv_nestedv2.c
> @@ -311,6 +311,10 @@ static int gs_msg_ops_vcpu_fill_info(struct kvmppc_gs_buff *gsb,
>  			rc = kvmppc_gse_put_u64(gsb, iden,
>  						vcpu->arch.vcore->vtb);
>  			break;
> +		case KVMPPC_GSID_DPDES:
> +			rc = kvmppc_gse_put_u64(gsb, iden,
> +						vcpu->arch.vcore->dpdes);
> +			break;
>  		case KVMPPC_GSID_LPCR:
>  			rc = kvmppc_gse_put_u64(gsb, iden,
>  						vcpu->arch.vcore->lpcr);
> @@ -543,6 +547,9 @@ static int gs_msg_ops_vcpu_refresh_info(struct kvmppc_gs_msg *gsm,
>  		case KVMPPC_GSID_VTB:
>  			vcpu->arch.vcore->vtb = kvmppc_gse_get_u64(gse);
>  			break;
> +		case KVMPPC_GSID_DPDES:
> +			vcpu->arch.vcore->dpdes = kvmppc_gse_get_u64(gse);
> +			break;
>  		case KVMPPC_GSID_LPCR:
>  			vcpu->arch.vcore->lpcr = kvmppc_gse_get_u64(gse);
>  			break;
> diff --git a/arch/powerpc/kvm/test-guest-state-buffer.c b/arch/powerpc/kvm/test-guest-state-buffer.c
> index 4720b8dc8837..2571ccc618c9 100644
> --- a/arch/powerpc/kvm/test-guest-state-buffer.c
> +++ b/arch/powerpc/kvm/test-guest-state-buffer.c
> @@ -151,7 +151,7 @@ static void test_gs_bitmap(struct kunit *test)
>  		i++;
>  	}
>  
> -	for (u16 iden = KVMPPC_GSID_GPR(0); iden <= KVMPPC_GSID_CTRL; iden++) {
> +	for (u16 iden = KVMPPC_GSID_GPR(0); iden <= KVMPPC_GSE_DW_REGS_END; iden++) {
>  		kvmppc_gsbm_set(&gsbm, iden);
>  		kvmppc_gsbm_set(&gsbm1, iden);
>  		KUNIT_EXPECT_TRUE(test, kvmppc_gsbm_test(&gsbm, iden));