| Message ID | 20211102094651.2071532-3-oupton@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Emulate the OS lock | expand |
On Tue, Nov 2, 2021 at 2:47 AM Oliver Upton <oupton@google.com> wrote: > > An upcoming change to KVM will context switch the OS Lock status between > guest/host. Add OSLSR_EL1 to the cpu context and handle guest reads > using the stored value. > > Wire up a custom handler for writes from userspace and prevent any of > the invariant bits from changing. > > Signed-off-by: Oliver Upton <oupton@google.com> > --- > arch/arm64/include/asm/kvm_host.h | 1 + > arch/arm64/kvm/sys_regs.c | 31 ++++++++++++++++++++++++------- > 2 files changed, 25 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index f8be56d5342b..c98f65c4a1f7 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -172,6 +172,7 @@ enum vcpu_sysreg { > MDSCR_EL1, /* Monitor Debug System Control Register */ > MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */ > DISR_EL1, /* Deferred Interrupt Status Register */ > + OSLSR_EL1, /* OS Lock Status Register */ Sorry Marc, forgot to move this up per your suggestion on the last series. Only caught it once the patch went out the door. -- Oliver
On Tue, Nov 2, 2021 at 2:51 AM Oliver Upton <oupton@google.com> wrote: > > On Tue, Nov 2, 2021 at 2:47 AM Oliver Upton <oupton@google.com> wrote: > > > > An upcoming change to KVM will context switch the OS Lock status between > > guest/host. Add OSLSR_EL1 to the cpu context and handle guest reads > > using the stored value. > > > > Wire up a custom handler for writes from userspace and prevent any of > > the invariant bits from changing. > > > > Signed-off-by: Oliver Upton <oupton@google.com> > > --- > > arch/arm64/include/asm/kvm_host.h | 1 + > > arch/arm64/kvm/sys_regs.c | 31 ++++++++++++++++++++++++------- > > 2 files changed, 25 insertions(+), 7 deletions(-) > > > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > > index f8be56d5342b..c98f65c4a1f7 100644 > > --- a/arch/arm64/include/asm/kvm_host.h > > +++ b/arch/arm64/include/asm/kvm_host.h > > @@ -172,6 +172,7 @@ enum vcpu_sysreg { > > MDSCR_EL1, /* Monitor Debug System Control Register */ > > MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */ > > DISR_EL1, /* Deferred Interrupt Status Register */ > > + OSLSR_EL1, /* OS Lock Status Register */ > > Sorry Marc, forgot to move this up per your suggestion on the last > series. Only caught it once the patch went out the door. Except for the above, Reviewed-by: Reiji Watanabe <reijiw@google.com> Thanks, Reiji
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index f8be56d5342b..c98f65c4a1f7 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -172,6 +172,7 @@ enum vcpu_sysreg { MDSCR_EL1, /* Monitor Debug System Control Register */ MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */ DISR_EL1, /* Deferred Interrupt Status Register */ + OSLSR_EL1, /* OS Lock Status Register */ /* Performance Monitors Registers */ PMCR_EL0, /* Control Register */ diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 17fa6ddf5405..0326b3df0736 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -291,12 +291,28 @@ static bool trap_oslsr_el1(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - if (p->is_write) { + if (p->is_write) return write_to_read_only(vcpu, p, r); - } else { - p->regval = (1 << 3); - return true; - } + + p->regval = __vcpu_sys_reg(vcpu, r->reg); + return true; +} + +static int set_oslsr_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, + const struct kvm_one_reg *reg, void __user *uaddr) +{ + u64 id = sys_reg_to_index(rd); + u64 val; + int err; + + err = reg_from_user(&val, uaddr, id); + if (err) + return err; + + if (val != rd->val) + return -EINVAL; + + return 0; } static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu, @@ -1441,7 +1457,8 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_MDRAR_EL1), trap_raz_wi }, { SYS_DESC(SYS_OSLAR_EL1), trap_raz_wi }, - { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1 }, + { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1, reset_val, OSLSR_EL1, 0x00000008, + .set_user = set_oslsr_el1, }, { SYS_DESC(SYS_OSDLR_EL1), trap_raz_wi }, { SYS_DESC(SYS_DBGPRCR_EL1), trap_raz_wi }, { SYS_DESC(SYS_DBGCLAIMSET_EL1), trap_raz_wi }, @@ -1916,7 +1933,7 @@ static const struct sys_reg_desc cp14_regs[] = { { Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi }, DBGBXVR(1), /* DBGOSLSR */ - { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1 }, + { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1, NULL, OSLSR_EL1 }, DBGBXVR(2), DBGBXVR(3), /* DBGOSDLR */
An upcoming change to KVM will context switch the OS Lock status between guest/host. Add OSLSR_EL1 to the cpu context and handle guest reads using the stored value. Wire up a custom handler for writes from userspace and prevent any of the invariant bits from changing. Signed-off-by: Oliver Upton <oupton@google.com> --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/sys_regs.c | 31 ++++++++++++++++++++++++------- 2 files changed, 25 insertions(+), 7 deletions(-)