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From: Andrew Jones <ajones@ventanamicro.com>
To: kvm-riscv@lists.infradead.org
Subject: [PATCH 1/1] RISC-V: KVM: No need to use mask when hart-index-bit is 0
Date: Wed, 22 May 2024 11:00:12 +0200	[thread overview]
Message-ID: <20240522-74009df58fb51008bae6cbaf@orel> (raw)
In-Reply-To: <20240415064905.25184-1-yongxuan.wang@sifive.com>

On Mon, Apr 15, 2024 at 02:49:04PM GMT, Yong-Xuan Wang wrote:
> When the maximum hart number within groups is 1, hart-index-bit is set to
> 0. Consequently, there is no need to restore the hart ID from IMSIC
> addresses and hart-index-bit settings. Currently, QEMU and kvmtool do not
> pass correct hart-index-bit values when the maximum hart number is a
> power of 2, thereby avoiding this issue. Corresponding patches for QEMU
> and kvmtool will also be dispatched.
> 
> Fixes: 89d01306e34d ("RISC-V: KVM: Implement device interface for AIA irqchip")
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
> ---
>  arch/riscv/kvm/aia_device.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/riscv/kvm/aia_device.c b/arch/riscv/kvm/aia_device.c
> index 0eb689351b7d..5cd407c6a8e4 100644
> --- a/arch/riscv/kvm/aia_device.c
> +++ b/arch/riscv/kvm/aia_device.c
> @@ -237,10 +237,11 @@ static gpa_t aia_imsic_ppn(struct kvm_aia *aia, gpa_t addr)
>  
>  static u32 aia_imsic_hart_index(struct kvm_aia *aia, gpa_t addr)
>  {
> -	u32 hart, group = 0;
> +	u32 hart = 0, group = 0;
>  
> -	hart = (addr >> (aia->nr_guest_bits + IMSIC_MMIO_PAGE_SHIFT)) &
> -		GENMASK_ULL(aia->nr_hart_bits - 1, 0);
> +	if (aia->nr_hart_bits)
> +		hart = (addr >> (aia->nr_guest_bits + IMSIC_MMIO_PAGE_SHIFT)) &
> +		       GENMASK_ULL(aia->nr_hart_bits - 1, 0);
>  	if (aia->nr_group_bits)
>  		group = (addr >> aia->nr_group_shift) &
>  			GENMASK_ULL(aia->nr_group_bits - 1, 0);
> -- 
> 2.17.1
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>


WARNING: multiple messages have this Message-ID (diff)
From: Andrew Jones <ajones@ventanamicro.com>
To: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Cc: linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org,
	 greentime.hu@sifive.com, vincent.chen@sifive.com,
	Anup Patel <anup@brainfault.org>,
	 Atish Patra <atishp@atishpatra.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	kvm@vger.kernel.org,  linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] RISC-V: KVM: No need to use mask when hart-index-bit is 0
Date: Wed, 22 May 2024 11:00:12 +0200	[thread overview]
Message-ID: <20240522-74009df58fb51008bae6cbaf@orel> (raw)
In-Reply-To: <20240415064905.25184-1-yongxuan.wang@sifive.com>

On Mon, Apr 15, 2024 at 02:49:04PM GMT, Yong-Xuan Wang wrote:
> When the maximum hart number within groups is 1, hart-index-bit is set to
> 0. Consequently, there is no need to restore the hart ID from IMSIC
> addresses and hart-index-bit settings. Currently, QEMU and kvmtool do not
> pass correct hart-index-bit values when the maximum hart number is a
> power of 2, thereby avoiding this issue. Corresponding patches for QEMU
> and kvmtool will also be dispatched.
> 
> Fixes: 89d01306e34d ("RISC-V: KVM: Implement device interface for AIA irqchip")
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
> ---
>  arch/riscv/kvm/aia_device.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/riscv/kvm/aia_device.c b/arch/riscv/kvm/aia_device.c
> index 0eb689351b7d..5cd407c6a8e4 100644
> --- a/arch/riscv/kvm/aia_device.c
> +++ b/arch/riscv/kvm/aia_device.c
> @@ -237,10 +237,11 @@ static gpa_t aia_imsic_ppn(struct kvm_aia *aia, gpa_t addr)
>  
>  static u32 aia_imsic_hart_index(struct kvm_aia *aia, gpa_t addr)
>  {
> -	u32 hart, group = 0;
> +	u32 hart = 0, group = 0;
>  
> -	hart = (addr >> (aia->nr_guest_bits + IMSIC_MMIO_PAGE_SHIFT)) &
> -		GENMASK_ULL(aia->nr_hart_bits - 1, 0);
> +	if (aia->nr_hart_bits)
> +		hart = (addr >> (aia->nr_guest_bits + IMSIC_MMIO_PAGE_SHIFT)) &
> +		       GENMASK_ULL(aia->nr_hart_bits - 1, 0);
>  	if (aia->nr_group_bits)
>  		group = (addr >> aia->nr_group_shift) &
>  			GENMASK_ULL(aia->nr_group_bits - 1, 0);
> -- 
> 2.17.1
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>

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linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

WARNING: multiple messages have this Message-ID (diff)
From: Andrew Jones <ajones@ventanamicro.com>
To: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Cc: linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org,
	 greentime.hu@sifive.com, vincent.chen@sifive.com,
	Anup Patel <anup@brainfault.org>,
	 Atish Patra <atishp@atishpatra.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	kvm@vger.kernel.org,  linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] RISC-V: KVM: No need to use mask when hart-index-bit is 0
Date: Wed, 22 May 2024 11:00:12 +0200	[thread overview]
Message-ID: <20240522-74009df58fb51008bae6cbaf@orel> (raw)
In-Reply-To: <20240415064905.25184-1-yongxuan.wang@sifive.com>

On Mon, Apr 15, 2024 at 02:49:04PM GMT, Yong-Xuan Wang wrote:
> When the maximum hart number within groups is 1, hart-index-bit is set to
> 0. Consequently, there is no need to restore the hart ID from IMSIC
> addresses and hart-index-bit settings. Currently, QEMU and kvmtool do not
> pass correct hart-index-bit values when the maximum hart number is a
> power of 2, thereby avoiding this issue. Corresponding patches for QEMU
> and kvmtool will also be dispatched.
> 
> Fixes: 89d01306e34d ("RISC-V: KVM: Implement device interface for AIA irqchip")
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
> ---
>  arch/riscv/kvm/aia_device.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/riscv/kvm/aia_device.c b/arch/riscv/kvm/aia_device.c
> index 0eb689351b7d..5cd407c6a8e4 100644
> --- a/arch/riscv/kvm/aia_device.c
> +++ b/arch/riscv/kvm/aia_device.c
> @@ -237,10 +237,11 @@ static gpa_t aia_imsic_ppn(struct kvm_aia *aia, gpa_t addr)
>  
>  static u32 aia_imsic_hart_index(struct kvm_aia *aia, gpa_t addr)
>  {
> -	u32 hart, group = 0;
> +	u32 hart = 0, group = 0;
>  
> -	hart = (addr >> (aia->nr_guest_bits + IMSIC_MMIO_PAGE_SHIFT)) &
> -		GENMASK_ULL(aia->nr_hart_bits - 1, 0);
> +	if (aia->nr_hart_bits)
> +		hart = (addr >> (aia->nr_guest_bits + IMSIC_MMIO_PAGE_SHIFT)) &
> +		       GENMASK_ULL(aia->nr_hart_bits - 1, 0);
>  	if (aia->nr_group_bits)
>  		group = (addr >> aia->nr_group_shift) &
>  			GENMASK_ULL(aia->nr_group_bits - 1, 0);
> -- 
> 2.17.1
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>

  parent reply	other threads:[~2024-05-22  9:00 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-15  6:49 [PATCH 1/1] RISC-V: KVM: No need to use mask when hart-index-bit is 0 Yong-Xuan Wang
2024-04-15  6:49 ` Yong-Xuan Wang
2024-04-15  6:49 ` Yong-Xuan Wang
2024-05-22  8:24 ` Yong-Xuan Wang
2024-05-22  8:24   ` Yong-Xuan Wang
2024-05-22  8:24   ` Yong-Xuan Wang
2024-05-22  9:00 ` Andrew Jones [this message]
2024-05-22  9:00   ` Andrew Jones
2024-05-22  9:00   ` Andrew Jones
2024-05-31  4:34 ` Anup Patel
2024-05-31  4:34   ` Anup Patel
2024-05-31  4:34   ` Anup Patel

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