| Message ID | 20230520150116.7451-1-waylingII@gmail.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | RISC-V: KVM: Redirect AMO load/store misaligned traps to guest | expand |
On Sat, May 20, 2023 at 8:31 PM wchen <waylingii@gmail.com> wrote: > > The M-mode redirects an unhandled misaligned trap back > to S-mode when not delegating it to VS-mode(hedeleg). > However, KVM running in HS-mode terminates the VS-mode > software when back from M-mode. > The KVM should redirect the trap back to VS-mode, and > let VS-mode trap handler decide the next step. > Here is a way to handle misaligned traps in KVM, > not only directing them to VS-mode or terminate it. > > Signed-off-by: wchen <waylingII@gmail.com> Looks good to me. Reviewed-by: Anup Patel <anup@brainfault.org> Regards, Anup > --- > arch/riscv/include/asm/csr.h | 2 ++ > arch/riscv/kvm/vcpu_exit.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h > index b6acb7ed1..917814a0f 100644 > --- a/arch/riscv/include/asm/csr.h > +++ b/arch/riscv/include/asm/csr.h > @@ -82,7 +82,9 @@ > #define EXC_INST_ACCESS 1 > #define EXC_INST_ILLEGAL 2 > #define EXC_BREAKPOINT 3 > +#define EXC_LOAD_MISALIGNED 4 > #define EXC_LOAD_ACCESS 5 > +#define EXC_STORE_MISALIGNED 6 > #define EXC_STORE_ACCESS 7 > #define EXC_SYSCALL 8 > #define EXC_HYPERVISOR_SYSCALL 9 > diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c > index 4ea101a73..2415722c0 100644 > --- a/arch/riscv/kvm/vcpu_exit.c > +++ b/arch/riscv/kvm/vcpu_exit.c > @@ -183,6 +183,8 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, > run->exit_reason = KVM_EXIT_UNKNOWN; > switch (trap->scause) { > case EXC_INST_ILLEGAL: > + case EXC_LOAD_MISALIGNED: > + case EXC_STORE_MISALIGNED: > if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) { > kvm_riscv_vcpu_trap_redirect(vcpu, trap); > ret = 1; > -- > 2.34.1 >
On Sat, May 20, 2023 at 8:31 PM wchen <waylingii@gmail.com> wrote: > > The M-mode redirects an unhandled misaligned trap back > to S-mode when not delegating it to VS-mode(hedeleg). > However, KVM running in HS-mode terminates the VS-mode > software when back from M-mode. > The KVM should redirect the trap back to VS-mode, and > let VS-mode trap handler decide the next step. > Here is a way to handle misaligned traps in KVM, > not only directing them to VS-mode or terminate it. > > Signed-off-by: wchen <waylingII@gmail.com> Queued this patch for 6.5 Thanks, Anup > --- > arch/riscv/include/asm/csr.h | 2 ++ > arch/riscv/kvm/vcpu_exit.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h > index b6acb7ed1..917814a0f 100644 > --- a/arch/riscv/include/asm/csr.h > +++ b/arch/riscv/include/asm/csr.h > @@ -82,7 +82,9 @@ > #define EXC_INST_ACCESS 1 > #define EXC_INST_ILLEGAL 2 > #define EXC_BREAKPOINT 3 > +#define EXC_LOAD_MISALIGNED 4 > #define EXC_LOAD_ACCESS 5 > +#define EXC_STORE_MISALIGNED 6 > #define EXC_STORE_ACCESS 7 > #define EXC_SYSCALL 8 > #define EXC_HYPERVISOR_SYSCALL 9 > diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c > index 4ea101a73..2415722c0 100644 > --- a/arch/riscv/kvm/vcpu_exit.c > +++ b/arch/riscv/kvm/vcpu_exit.c > @@ -183,6 +183,8 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, > run->exit_reason = KVM_EXIT_UNKNOWN; > switch (trap->scause) { > case EXC_INST_ILLEGAL: > + case EXC_LOAD_MISALIGNED: > + case EXC_STORE_MISALIGNED: > if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) { > kvm_riscv_vcpu_trap_redirect(vcpu, trap); > ret = 1; > -- > 2.34.1 >
diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h index b6acb7ed1..917814a0f 100644 --- a/arch/riscv/include/asm/csr.h +++ b/arch/riscv/include/asm/csr.h @@ -82,7 +82,9 @@ #define EXC_INST_ACCESS 1 #define EXC_INST_ILLEGAL 2 #define EXC_BREAKPOINT 3 +#define EXC_LOAD_MISALIGNED 4 #define EXC_LOAD_ACCESS 5 +#define EXC_STORE_MISALIGNED 6 #define EXC_STORE_ACCESS 7 #define EXC_SYSCALL 8 #define EXC_HYPERVISOR_SYSCALL 9 diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c index 4ea101a73..2415722c0 100644 --- a/arch/riscv/kvm/vcpu_exit.c +++ b/arch/riscv/kvm/vcpu_exit.c @@ -183,6 +183,8 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, run->exit_reason = KVM_EXIT_UNKNOWN; switch (trap->scause) { case EXC_INST_ILLEGAL: + case EXC_LOAD_MISALIGNED: + case EXC_STORE_MISALIGNED: if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) { kvm_riscv_vcpu_trap_redirect(vcpu, trap); ret = 1;
The M-mode redirects an unhandled misaligned trap back to S-mode when not delegating it to VS-mode(hedeleg). However, KVM running in HS-mode terminates the VS-mode software when back from M-mode. The KVM should redirect the trap back to VS-mode, and let VS-mode trap handler decide the next step. Here is a way to handle misaligned traps in KVM, not only directing them to VS-mode or terminate it. Signed-off-by: wchen <waylingII@gmail.com> --- arch/riscv/include/asm/csr.h | 2 ++ arch/riscv/kvm/vcpu_exit.c | 2 ++ 2 files changed, 4 insertions(+)