* [PATCH 1/1] RISC-V: KVM: No need to use mask when hart-index-bit is 0
@ 2024-04-15 6:49 Yong-Xuan Wang
2024-05-22 8:24 ` Yong-Xuan Wang
2024-05-22 9:00 ` Andrew Jones
0 siblings, 2 replies; 3+ messages in thread
From: Yong-Xuan Wang @ 2024-04-15 6:49 UTC (permalink / raw)
To: linux-riscv, kvm-riscv
Cc: greentime.hu, vincent.chen, Yong-Xuan Wang, Anup Patel,
Atish Patra, Paul Walmsley, Palmer Dabbelt, Albert Ou, kvm,
linux-kernel
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
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH 1/1] RISC-V: KVM: No need to use mask when hart-index-bit is 0
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
@ 2024-05-22 8:24 ` Yong-Xuan Wang
2024-05-22 9:00 ` Andrew Jones
1 sibling, 0 replies; 3+ messages in thread
From: Yong-Xuan Wang @ 2024-05-22 8:24 UTC (permalink / raw)
To: linux-riscv, kvm-riscv
Cc: greentime.hu, vincent.chen, Anup Patel, Atish Patra,
Paul Walmsley, Palmer Dabbelt, Albert Ou, kvm, linux-kernel
Ping
On Mon, Apr 15, 2024 at 2:49 PM Yong-Xuan Wang <yongxuan.wang@sifive.com> 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
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH 1/1] RISC-V: KVM: No need to use mask when hart-index-bit is 0
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
2024-05-22 8:24 ` Yong-Xuan Wang
@ 2024-05-22 9:00 ` Andrew Jones
1 sibling, 0 replies; 3+ messages in thread
From: Andrew Jones @ 2024-05-22 9:00 UTC (permalink / raw)
To: Yong-Xuan Wang
Cc: linux-riscv, kvm-riscv, greentime.hu, vincent.chen, Anup Patel,
Atish Patra, Paul Walmsley, Palmer Dabbelt, Albert Ou, kvm,
linux-kernel
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>
^ permalink raw reply [flat|nested] 3+ messages in thread
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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
2024-05-22 8:24 ` Yong-Xuan Wang
2024-05-22 9:00 ` Andrew Jones
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