| Message ID | 20201126134641.35231-2-drjones@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Fix DEMUX register access | expand |
On 2020-11-26 13:46, Andrew Jones wrote: > Not counting TnD, which KVM doesn't currently consider, CSSELR_EL1 > can have a maximum value of 0b1101 (13), which corresponds to an > instruction cache at level 7. With CSSELR_MAX set to 12 we can > only select up to cache level 6. Change it to 14. > > Signed-off-by: Andrew Jones <drjones@redhat.com> > --- > arch/arm64/kvm/sys_regs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index c1fac9836af1..ef453f7827fa 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -169,7 +169,7 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 > val, int reg) > static u32 cache_levels; > > /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ > -#define CSSELR_MAX 12 > +#define CSSELR_MAX 14 > > /* Which cache CCSIDR represents depends on CSSELR value. */ > static u32 get_ccsidr(u32 csselr) Huh, nice catch. Do we need a CC: stable tag for this? Thanks, M.
On Thu, Nov 26, 2020 at 02:13:44PM +0000, Marc Zyngier wrote: > On 2020-11-26 13:46, Andrew Jones wrote: > > Not counting TnD, which KVM doesn't currently consider, CSSELR_EL1 > > can have a maximum value of 0b1101 (13), which corresponds to an > > instruction cache at level 7. With CSSELR_MAX set to 12 we can > > only select up to cache level 6. Change it to 14. > > > > Signed-off-by: Andrew Jones <drjones@redhat.com> > > --- > > arch/arm64/kvm/sys_regs.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > > index c1fac9836af1..ef453f7827fa 100644 > > --- a/arch/arm64/kvm/sys_regs.c > > +++ b/arch/arm64/kvm/sys_regs.c > > @@ -169,7 +169,7 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 > > val, int reg) > > static u32 cache_levels; > > > > /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ > > -#define CSSELR_MAX 12 > > +#define CSSELR_MAX 14 > > > > /* Which cache CCSIDR represents depends on CSSELR value. */ > > static u32 get_ccsidr(u32 csselr) > > Huh, nice catch. Do we need a CC: stable tag for this? > Hi Marc, I wasn't thinking so, because I'm not expecting there to actually be hardware with seven cache levels in the wild any time soon. You have more knowledge about what's out there and coming, though, so feel free CC stable if needed. Thanks, drew
On 2020-11-26 14:32, Andrew Jones wrote: > On Thu, Nov 26, 2020 at 02:13:44PM +0000, Marc Zyngier wrote: >> On 2020-11-26 13:46, Andrew Jones wrote: >> > Not counting TnD, which KVM doesn't currently consider, CSSELR_EL1 >> > can have a maximum value of 0b1101 (13), which corresponds to an >> > instruction cache at level 7. With CSSELR_MAX set to 12 we can >> > only select up to cache level 6. Change it to 14. >> > >> > Signed-off-by: Andrew Jones <drjones@redhat.com> >> > --- >> > arch/arm64/kvm/sys_regs.c | 2 +- >> > 1 file changed, 1 insertion(+), 1 deletion(-) >> > >> > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c >> > index c1fac9836af1..ef453f7827fa 100644 >> > --- a/arch/arm64/kvm/sys_regs.c >> > +++ b/arch/arm64/kvm/sys_regs.c >> > @@ -169,7 +169,7 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 >> > val, int reg) >> > static u32 cache_levels; >> > >> > /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ >> > -#define CSSELR_MAX 12 >> > +#define CSSELR_MAX 14 >> > >> > /* Which cache CCSIDR represents depends on CSSELR value. */ >> > static u32 get_ccsidr(u32 csselr) >> >> Huh, nice catch. Do we need a CC: stable tag for this? >> > > Hi Marc, > > I wasn't thinking so, because I'm not expecting there to actually > be hardware with seven cache levels in the wild any time soon. You > have more knowledge about what's out there and coming, though, so > feel free CC stable if needed. That's actually what I was wondering, whether you had seen that in the wild already. Since you haven't (and I'm not aware of such a monstrosity), I'll queue it for 5.11. Do you want me to take the selftest stuff at the same time? Thanks, M.
On Thu, Nov 26, 2020 at 02:34:05PM +0000, Marc Zyngier wrote: > On 2020-11-26 14:32, Andrew Jones wrote: > > On Thu, Nov 26, 2020 at 02:13:44PM +0000, Marc Zyngier wrote: > > > On 2020-11-26 13:46, Andrew Jones wrote: > > > > Not counting TnD, which KVM doesn't currently consider, CSSELR_EL1 > > > > can have a maximum value of 0b1101 (13), which corresponds to an > > > > instruction cache at level 7. With CSSELR_MAX set to 12 we can > > > > only select up to cache level 6. Change it to 14. > > > > > > > > Signed-off-by: Andrew Jones <drjones@redhat.com> > > > > --- > > > > arch/arm64/kvm/sys_regs.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > > > > index c1fac9836af1..ef453f7827fa 100644 > > > > --- a/arch/arm64/kvm/sys_regs.c > > > > +++ b/arch/arm64/kvm/sys_regs.c > > > > @@ -169,7 +169,7 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 > > > > val, int reg) > > > > static u32 cache_levels; > > > > > > > > /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ > > > > -#define CSSELR_MAX 12 > > > > +#define CSSELR_MAX 14 > > > > > > > > /* Which cache CCSIDR represents depends on CSSELR value. */ > > > > static u32 get_ccsidr(u32 csselr) > > > > > > Huh, nice catch. Do we need a CC: stable tag for this? > > > > > > > Hi Marc, > > > > I wasn't thinking so, because I'm not expecting there to actually > > be hardware with seven cache levels in the wild any time soon. You > > have more knowledge about what's out there and coming, though, so > > feel free CC stable if needed. > > That's actually what I was wondering, whether you had seen that in the > wild already. Since you haven't (and I'm not aware of such a monstrosity), > I'll queue it for 5.11. > > Do you want me to take the selftest stuff at the same time? > Yes, please :) Thanks, drew
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index c1fac9836af1..ef453f7827fa 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -169,7 +169,7 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) static u32 cache_levels; /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ -#define CSSELR_MAX 12 +#define CSSELR_MAX 14 /* Which cache CCSIDR represents depends on CSSELR value. */ static u32 get_ccsidr(u32 csselr)
Not counting TnD, which KVM doesn't currently consider, CSSELR_EL1 can have a maximum value of 0b1101 (13), which corresponds to an instruction cache at level 7. With CSSELR_MAX set to 12 we can only select up to cache level 6. Change it to 14. Signed-off-by: Andrew Jones <drjones@redhat.com> --- arch/arm64/kvm/sys_regs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)