| Message ID | 20240522084949.123148-1-gautam@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v1,RESEND] arch/powerpc/kvm: Fix doorbell emulation by adding DPDES support | expand |
On Wed May 22, 2024 at 6:49 PM AEST, Gautam Menghani wrote: > Doorbell emulation is broken for KVM on PowerVM guests as support for > DPDES was not added in the initial patch series. Due to this, a KVM on > PowerVM guest cannot be booted with the XICS interrupt controller as > doorbells are to be setup in the initial probe path when using XICS > (pSeries_smp_probe()). Add DPDES support in the host KVM code to fix > doorbell emulation. This is broken when the KVM guest has SMT > 1? Or is it broken for SMT=1 as well? Can you explain a bit more of what breaks if it's the latter? > Fixes: 6ccbbc33f06a ("KVM: PPC: Add helper library for Guest State Buffers") > Cc: stable@vger.kernel.org > Signed-off-by: Gautam Menghani <gautam@linux.ibm.com> > --- > v1 -> v1 resend: > 1. Add the stable tag > > Documentation/arch/powerpc/kvm-nested.rst | 4 +++- > arch/powerpc/include/asm/guest-state-buffer.h | 3 ++- > arch/powerpc/include/asm/kvm_book3s.h | 1 + > arch/powerpc/kvm/book3s_hv.c | 14 +++++++++++++- > arch/powerpc/kvm/book3s_hv_nestedv2.c | 7 +++++++ > arch/powerpc/kvm/test-guest-state-buffer.c | 2 +- > 6 files changed, 27 insertions(+), 4 deletions(-) > > diff --git a/Documentation/arch/powerpc/kvm-nested.rst b/Documentation/arch/powerpc/kvm-nested.rst > index 630602a8aa00..5defd13cc6c1 100644 > --- a/Documentation/arch/powerpc/kvm-nested.rst > +++ b/Documentation/arch/powerpc/kvm-nested.rst > @@ -546,7 +546,9 @@ table information. > +--------+-------+----+--------+----------------------------------+ > | 0x1052 | 0x08 | RW | T | CTRL | > +--------+-------+----+--------+----------------------------------+ > -| 0x1053-| | | | Reserved | > +| 0x1053 | 0x08 | RW | T | DPDES | > ++--------+-------+----+--------+----------------------------------+ > +| 0x1054-| | | | Reserved | > | 0x1FFF | | | | | > +--------+-------+----+--------+----------------------------------+ > | 0x2000 | 0x04 | RW | T | CR | > diff --git a/arch/powerpc/include/asm/guest-state-buffer.h b/arch/powerpc/include/asm/guest-state-buffer.h > index 808149f31576..d107abe1468f 100644 > --- a/arch/powerpc/include/asm/guest-state-buffer.h > +++ b/arch/powerpc/include/asm/guest-state-buffer.h > @@ -81,6 +81,7 @@ > #define KVMPPC_GSID_HASHKEYR 0x1050 > #define KVMPPC_GSID_HASHPKEYR 0x1051 > #define KVMPPC_GSID_CTRL 0x1052 > +#define KVMPPC_GSID_DPDES 0x1053 > > #define KVMPPC_GSID_CR 0x2000 > #define KVMPPC_GSID_PIDR 0x2001 > @@ -110,7 +111,7 @@ > #define KVMPPC_GSE_META_COUNT (KVMPPC_GSE_META_END - KVMPPC_GSE_META_START + 1) > > #define KVMPPC_GSE_DW_REGS_START KVMPPC_GSID_GPR(0) > -#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_CTRL > +#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_DPDES > #define KVMPPC_GSE_DW_REGS_COUNT \ > (KVMPPC_GSE_DW_REGS_END - KVMPPC_GSE_DW_REGS_START + 1) > > diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h > index 3e1e2a698c9e..10618622d7ef 100644 > --- a/arch/powerpc/include/asm/kvm_book3s.h > +++ b/arch/powerpc/include/asm/kvm_book3s.h > @@ -594,6 +594,7 @@ static inline u##size kvmppc_get_##reg(struct kvm_vcpu *vcpu) \ > > > KVMPPC_BOOK3S_VCORE_ACCESSOR(vtb, 64, KVMPPC_GSID_VTB) > +KVMPPC_BOOK3S_VCORE_ACCESSOR(dpdes, 64, KVMPPC_GSID_DPDES) > KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(arch_compat, 32, KVMPPC_GSID_LOGICAL_PVR) > KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(lpcr, 64, KVMPPC_GSID_LPCR) > KVMPPC_BOOK3S_VCORE_ACCESSOR_SET(tb_offset, 64, KVMPPC_GSID_TB_OFFSET) > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 35cb014a0c51..cf285e5153ba 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -4116,6 +4116,11 @@ static int kvmhv_vcpu_entry_nestedv2(struct kvm_vcpu *vcpu, u64 time_limit, > int trap; > long rc; > > + if (vcpu->arch.doorbell_request) { > + vcpu->arch.doorbell_request = 0; > + kvmppc_set_dpdes(vcpu, 1); > + } This probably looks okay... hmm, is the v1 KVM emulating doorbells correctly for SMT L2 guests? I wonder if doorbell emulation isn't broken there too because the L1 code looks to be passing in vc->dpdes but all the POWER9 emulation code uses doorbell_request. > + > io = &vcpu->arch.nestedv2_io; > > msr = mfmsr(); > @@ -4278,9 +4283,16 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, > if (kvmhv_on_pseries()) { > if (kvmhv_is_nestedv1()) > trap = kvmhv_vcpu_entry_p9_nested(vcpu, time_limit, lpcr, tb); > - else > + else { > trap = kvmhv_vcpu_entry_nestedv2(vcpu, time_limit, lpcr, tb); > > + /* Remember doorbell if it is pending */ > + if (kvmppc_get_dpdes(vcpu)) { > + vcpu->arch.doorbell_request = 1; > + kvmppc_set_dpdes(vcpu, 0); > + } This is adding an extra get state for every entry, not good. I don't think it's actually needed though. I don't think the L1 cares at this stage what the L2 DPDES state is. So you sholud be able to drop this hunk. > + } > + > /* H_CEDE has to be handled now, not later */ > if (trap == BOOK3S_INTERRUPT_SYSCALL && !nested && > kvmppc_get_gpr(vcpu, 3) == H_CEDE) { > diff --git a/arch/powerpc/kvm/book3s_hv_nestedv2.c b/arch/powerpc/kvm/book3s_hv_nestedv2.c > index 8e6f5355f08b..36863fff2a99 100644 > --- a/arch/powerpc/kvm/book3s_hv_nestedv2.c > +++ b/arch/powerpc/kvm/book3s_hv_nestedv2.c > @@ -311,6 +311,10 @@ static int gs_msg_ops_vcpu_fill_info(struct kvmppc_gs_buff *gsb, > rc = kvmppc_gse_put_u64(gsb, iden, > vcpu->arch.vcore->vtb); > break; > + case KVMPPC_GSID_DPDES: > + rc = kvmppc_gse_put_u64(gsb, iden, > + vcpu->arch.vcore->dpdes); > + break; > case KVMPPC_GSID_LPCR: > rc = kvmppc_gse_put_u64(gsb, iden, > vcpu->arch.vcore->lpcr); > @@ -543,6 +547,9 @@ static int gs_msg_ops_vcpu_refresh_info(struct kvmppc_gs_msg *gsm, > case KVMPPC_GSID_VTB: > vcpu->arch.vcore->vtb = kvmppc_gse_get_u64(gse); > break; > + case KVMPPC_GSID_DPDES: > + vcpu->arch.vcore->dpdes = kvmppc_gse_get_u64(gse); > + break; > case KVMPPC_GSID_LPCR: > vcpu->arch.vcore->lpcr = kvmppc_gse_get_u64(gse); > break; I would split all the wiring up of the DPDES GSID stuff into its own patch, it obviously looks fine. > diff --git a/arch/powerpc/kvm/test-guest-state-buffer.c b/arch/powerpc/kvm/test-guest-state-buffer.c > index 4720b8dc8837..91ae660cfe21 100644 > --- a/arch/powerpc/kvm/test-guest-state-buffer.c > +++ b/arch/powerpc/kvm/test-guest-state-buffer.c > @@ -151,7 +151,7 @@ static void test_gs_bitmap(struct kunit *test) > i++; > } > > - for (u16 iden = KVMPPC_GSID_GPR(0); iden <= KVMPPC_GSID_CTRL; iden++) { > + for (u16 iden = KVMPPC_GSID_GPR(0); iden <= KVMPPC_GSID_DPDES; iden++) { > kvmppc_gsbm_set(&gsbm, iden); > kvmppc_gsbm_set(&gsbm1, iden); > KUNIT_EXPECT_TRUE(test, kvmppc_gsbm_test(&gsbm, iden)); It would be good to have a _LAST define for such loops. It's very easy to miss when adding KVMPPC_GSID_DPDES that you need to grep for KVMPPC_GSID_CTRL. Very easy to see that you need to update _LAST. You just need to work out a good name for it since there's a few "namespaces" of numbers with similar prefix. Good luck :) Thanks, Nick
On Mon, Jun 03, 2024 at 03:42:22PM GMT, Nicholas Piggin wrote: > On Wed May 22, 2024 at 6:49 PM AEST, Gautam Menghani wrote: > > Doorbell emulation is broken for KVM on PowerVM guests as support for > > DPDES was not added in the initial patch series. Due to this, a KVM on > > PowerVM guest cannot be booted with the XICS interrupt controller as > > doorbells are to be setup in the initial probe path when using XICS > > (pSeries_smp_probe()). Add DPDES support in the host KVM code to fix > > doorbell emulation. > > This is broken when the KVM guest has SMT > 1? Or is it broken for SMT=1 > as well? Can you explain a bit more of what breaks if it's the latter? Yes, doorbells are only setup when we use SMT>1 and interrupt controller is XICS. So without this patch, L2 KOP guest with XICS IC mode and SMT>1 does not boot. SMT 1 is fine in all cases. > > > Fixes: 6ccbbc33f06a ("KVM: PPC: Add helper library for Guest State Buffers") > > Cc: stable@vger.kernel.org > > Signed-off-by: Gautam Menghani <gautam@linux.ibm.com> > > --- > > v1 -> v1 resend: > > 1. Add the stable tag > > > > Documentation/arch/powerpc/kvm-nested.rst | 4 +++- > > arch/powerpc/include/asm/guest-state-buffer.h | 3 ++- > > arch/powerpc/include/asm/kvm_book3s.h | 1 + > > arch/powerpc/kvm/book3s_hv.c | 14 +++++++++++++- > > arch/powerpc/kvm/book3s_hv_nestedv2.c | 7 +++++++ > > arch/powerpc/kvm/test-guest-state-buffer.c | 2 +- > > 6 files changed, 27 insertions(+), 4 deletions(-) > > > > diff --git a/Documentation/arch/powerpc/kvm-nested.rst b/Documentation/arch/powerpc/kvm-nested.rst > > index 630602a8aa00..5defd13cc6c1 100644 > > --- a/Documentation/arch/powerpc/kvm-nested.rst > > +++ b/Documentation/arch/powerpc/kvm-nested.rst > > @@ -546,7 +546,9 @@ table information. > > +--------+-------+----+--------+----------------------------------+ > > | 0x1052 | 0x08 | RW | T | CTRL | > > +--------+-------+----+--------+----------------------------------+ > > -| 0x1053-| | | | Reserved | > > +| 0x1053 | 0x08 | RW | T | DPDES | > > ++--------+-------+----+--------+----------------------------------+ > > +| 0x1054-| | | | Reserved | > > | 0x1FFF | | | | | > > +--------+-------+----+--------+----------------------------------+ > > | 0x2000 | 0x04 | RW | T | CR | > > diff --git a/arch/powerpc/include/asm/guest-state-buffer.h b/arch/powerpc/include/asm/guest-state-buffer.h > > index 808149f31576..d107abe1468f 100644 > > --- a/arch/powerpc/include/asm/guest-state-buffer.h > > +++ b/arch/powerpc/include/asm/guest-state-buffer.h > > @@ -81,6 +81,7 @@ > > #define KVMPPC_GSID_HASHKEYR 0x1050 > > #define KVMPPC_GSID_HASHPKEYR 0x1051 > > #define KVMPPC_GSID_CTRL 0x1052 > > +#define KVMPPC_GSID_DPDES 0x1053 > > > > #define KVMPPC_GSID_CR 0x2000 > > #define KVMPPC_GSID_PIDR 0x2001 > > @@ -110,7 +111,7 @@ > > #define KVMPPC_GSE_META_COUNT (KVMPPC_GSE_META_END - KVMPPC_GSE_META_START + 1) > > > > #define KVMPPC_GSE_DW_REGS_START KVMPPC_GSID_GPR(0) > > -#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_CTRL > > +#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_DPDES > > #define KVMPPC_GSE_DW_REGS_COUNT \ > > (KVMPPC_GSE_DW_REGS_END - KVMPPC_GSE_DW_REGS_START + 1) > > > > diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h > > index 3e1e2a698c9e..10618622d7ef 100644 > > --- a/arch/powerpc/include/asm/kvm_book3s.h > > +++ b/arch/powerpc/include/asm/kvm_book3s.h > > @@ -594,6 +594,7 @@ static inline u##size kvmppc_get_##reg(struct kvm_vcpu *vcpu) \ > > > > > > KVMPPC_BOOK3S_VCORE_ACCESSOR(vtb, 64, KVMPPC_GSID_VTB) > > +KVMPPC_BOOK3S_VCORE_ACCESSOR(dpdes, 64, KVMPPC_GSID_DPDES) > > KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(arch_compat, 32, KVMPPC_GSID_LOGICAL_PVR) > > KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(lpcr, 64, KVMPPC_GSID_LPCR) > > KVMPPC_BOOK3S_VCORE_ACCESSOR_SET(tb_offset, 64, KVMPPC_GSID_TB_OFFSET) > > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > > index 35cb014a0c51..cf285e5153ba 100644 > > --- a/arch/powerpc/kvm/book3s_hv.c > > +++ b/arch/powerpc/kvm/book3s_hv.c > > @@ -4116,6 +4116,11 @@ static int kvmhv_vcpu_entry_nestedv2(struct kvm_vcpu *vcpu, u64 time_limit, > > int trap; > > long rc; > > > > + if (vcpu->arch.doorbell_request) { > > + vcpu->arch.doorbell_request = 0; > > + kvmppc_set_dpdes(vcpu, 1); > > + } > > This probably looks okay... hmm, is the v1 KVM emulating doorbells > correctly for SMT L2 guests? I wonder if doorbell emulation isn't > broken there too because the L1 code looks to be passing in vc->dpdes > but all the POWER9 emulation code uses doorbell_request. > Yes launching SMT L2 on V1 API fails with a kernel Oops, I'll see if I can fix that as well. > > + > > io = &vcpu->arch.nestedv2_io; > > > > msr = mfmsr(); > > @@ -4278,9 +4283,16 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, > > if (kvmhv_on_pseries()) { > > if (kvmhv_is_nestedv1()) > > trap = kvmhv_vcpu_entry_p9_nested(vcpu, time_limit, lpcr, tb); > > - else > > + else { > > trap = kvmhv_vcpu_entry_nestedv2(vcpu, time_limit, lpcr, tb); > > > > + /* Remember doorbell if it is pending */ > > + if (kvmppc_get_dpdes(vcpu)) { > > + vcpu->arch.doorbell_request = 1; > > + kvmppc_set_dpdes(vcpu, 0); > > + } > > This is adding an extra get state for every entry, not good. I don't > think it's actually needed though. I don't think the L1 cares at this > stage what the L2 DPDES state is. So you sholud be able to drop this > hunk. > Yes ok. > > + } > > + > > /* H_CEDE has to be handled now, not later */ > > if (trap == BOOK3S_INTERRUPT_SYSCALL && !nested && > > kvmppc_get_gpr(vcpu, 3) == H_CEDE) { > > diff --git a/arch/powerpc/kvm/book3s_hv_nestedv2.c b/arch/powerpc/kvm/book3s_hv_nestedv2.c > > index 8e6f5355f08b..36863fff2a99 100644 > > --- a/arch/powerpc/kvm/book3s_hv_nestedv2.c > > +++ b/arch/powerpc/kvm/book3s_hv_nestedv2.c > > @@ -311,6 +311,10 @@ static int gs_msg_ops_vcpu_fill_info(struct kvmppc_gs_buff *gsb, > > rc = kvmppc_gse_put_u64(gsb, iden, > > vcpu->arch.vcore->vtb); > > break; > > + case KVMPPC_GSID_DPDES: > > + rc = kvmppc_gse_put_u64(gsb, iden, > > + vcpu->arch.vcore->dpdes); > > + break; > > case KVMPPC_GSID_LPCR: > > rc = kvmppc_gse_put_u64(gsb, iden, > > vcpu->arch.vcore->lpcr); > > @@ -543,6 +547,9 @@ static int gs_msg_ops_vcpu_refresh_info(struct kvmppc_gs_msg *gsm, > > case KVMPPC_GSID_VTB: > > vcpu->arch.vcore->vtb = kvmppc_gse_get_u64(gse); > > break; > > + case KVMPPC_GSID_DPDES: > > + vcpu->arch.vcore->dpdes = kvmppc_gse_get_u64(gse); > > + break; > > case KVMPPC_GSID_LPCR: > > vcpu->arch.vcore->lpcr = kvmppc_gse_get_u64(gse); > > break; > > I would split all the wiring up of the DPDES GSID stuff into its own > patch, it obviously looks fine. > Noted, will do. > > diff --git a/arch/powerpc/kvm/test-guest-state-buffer.c b/arch/powerpc/kvm/test-guest-state-buffer.c > > index 4720b8dc8837..91ae660cfe21 100644 > > --- a/arch/powerpc/kvm/test-guest-state-buffer.c > > +++ b/arch/powerpc/kvm/test-guest-state-buffer.c > > @@ -151,7 +151,7 @@ static void test_gs_bitmap(struct kunit *test) > > i++; > > } > > > > - for (u16 iden = KVMPPC_GSID_GPR(0); iden <= KVMPPC_GSID_CTRL; iden++) { > > + for (u16 iden = KVMPPC_GSID_GPR(0); iden <= KVMPPC_GSID_DPDES; iden++) { > > kvmppc_gsbm_set(&gsbm, iden); > > kvmppc_gsbm_set(&gsbm1, iden); > > KUNIT_EXPECT_TRUE(test, kvmppc_gsbm_test(&gsbm, iden)); > > It would be good to have a _LAST define for such loops. It's very easy > to miss when adding KVMPPC_GSID_DPDES that you need to grep for > KVMPPC_GSID_CTRL. Very easy to see that you need to update _LAST. > > You just need to work out a good name for it since there's a few > "namespaces" of numbers with similar prefix. Good luck :) > Well we already have a "KVMPPC_GSE_DW_REGS_END" defined, just missed to use that. > Thanks, > Nick
On Mon Jun 3, 2024 at 5:09 PM AEST, Gautam Menghani wrote: > On Mon, Jun 03, 2024 at 03:42:22PM GMT, Nicholas Piggin wrote: > > On Wed May 22, 2024 at 6:49 PM AEST, Gautam Menghani wrote: > > > Doorbell emulation is broken for KVM on PowerVM guests as support for > > > DPDES was not added in the initial patch series. Due to this, a KVM on > > > PowerVM guest cannot be booted with the XICS interrupt controller as > > > doorbells are to be setup in the initial probe path when using XICS > > > (pSeries_smp_probe()). Add DPDES support in the host KVM code to fix > > > doorbell emulation. > > > > This is broken when the KVM guest has SMT > 1? Or is it broken for SMT=1 > > as well? Can you explain a bit more of what breaks if it's the latter? > > Yes, doorbells are only setup when we use SMT>1 and interrupt controller > is XICS. So without this patch, L2 KOP guest with XICS IC mode and SMT>1 > does not boot. SMT 1 is fine in all cases. Okay good. Make that clear in the changelog, ideally if you can give a recipe the reader is able to recreate is good too, (e.g., run the guest machine with -smp 4,threads=4 and xive=off boot parameter). > > > Fixes: 6ccbbc33f06a ("KVM: PPC: Add helper library for Guest State Buffers") > > > Cc: stable@vger.kernel.org > > > Signed-off-by: Gautam Menghani <gautam@linux.ibm.com> > > > --- > > > v1 -> v1 resend: > > > 1. Add the stable tag > > > > > > Documentation/arch/powerpc/kvm-nested.rst | 4 +++- > > > arch/powerpc/include/asm/guest-state-buffer.h | 3 ++- > > > arch/powerpc/include/asm/kvm_book3s.h | 1 + > > > arch/powerpc/kvm/book3s_hv.c | 14 +++++++++++++- > > > arch/powerpc/kvm/book3s_hv_nestedv2.c | 7 +++++++ > > > arch/powerpc/kvm/test-guest-state-buffer.c | 2 +- > > > 6 files changed, 27 insertions(+), 4 deletions(-) > > > > > > diff --git a/Documentation/arch/powerpc/kvm-nested.rst b/Documentation/arch/powerpc/kvm-nested.rst > > > index 630602a8aa00..5defd13cc6c1 100644 > > > --- a/Documentation/arch/powerpc/kvm-nested.rst > > > +++ b/Documentation/arch/powerpc/kvm-nested.rst > > > @@ -546,7 +546,9 @@ table information. > > > +--------+-------+----+--------+----------------------------------+ > > > | 0x1052 | 0x08 | RW | T | CTRL | > > > +--------+-------+----+--------+----------------------------------+ > > > -| 0x1053-| | | | Reserved | > > > +| 0x1053 | 0x08 | RW | T | DPDES | > > > ++--------+-------+----+--------+----------------------------------+ > > > +| 0x1054-| | | | Reserved | > > > | 0x1FFF | | | | | > > > +--------+-------+----+--------+----------------------------------+ > > > | 0x2000 | 0x04 | RW | T | CR | > > > diff --git a/arch/powerpc/include/asm/guest-state-buffer.h b/arch/powerpc/include/asm/guest-state-buffer.h > > > index 808149f31576..d107abe1468f 100644 > > > --- a/arch/powerpc/include/asm/guest-state-buffer.h > > > +++ b/arch/powerpc/include/asm/guest-state-buffer.h > > > @@ -81,6 +81,7 @@ > > > #define KVMPPC_GSID_HASHKEYR 0x1050 > > > #define KVMPPC_GSID_HASHPKEYR 0x1051 > > > #define KVMPPC_GSID_CTRL 0x1052 > > > +#define KVMPPC_GSID_DPDES 0x1053 > > > > > > #define KVMPPC_GSID_CR 0x2000 > > > #define KVMPPC_GSID_PIDR 0x2001 > > > @@ -110,7 +111,7 @@ > > > #define KVMPPC_GSE_META_COUNT (KVMPPC_GSE_META_END - KVMPPC_GSE_META_START + 1) > > > > > > #define KVMPPC_GSE_DW_REGS_START KVMPPC_GSID_GPR(0) > > > -#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_CTRL > > > +#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_DPDES > > > #define KVMPPC_GSE_DW_REGS_COUNT \ > > > (KVMPPC_GSE_DW_REGS_END - KVMPPC_GSE_DW_REGS_START + 1) > > > > > > diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h > > > index 3e1e2a698c9e..10618622d7ef 100644 > > > --- a/arch/powerpc/include/asm/kvm_book3s.h > > > +++ b/arch/powerpc/include/asm/kvm_book3s.h > > > @@ -594,6 +594,7 @@ static inline u##size kvmppc_get_##reg(struct kvm_vcpu *vcpu) \ > > > > > > > > > KVMPPC_BOOK3S_VCORE_ACCESSOR(vtb, 64, KVMPPC_GSID_VTB) > > > +KVMPPC_BOOK3S_VCORE_ACCESSOR(dpdes, 64, KVMPPC_GSID_DPDES) > > > KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(arch_compat, 32, KVMPPC_GSID_LOGICAL_PVR) > > > KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(lpcr, 64, KVMPPC_GSID_LPCR) > > > KVMPPC_BOOK3S_VCORE_ACCESSOR_SET(tb_offset, 64, KVMPPC_GSID_TB_OFFSET) > > > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > > > index 35cb014a0c51..cf285e5153ba 100644 > > > --- a/arch/powerpc/kvm/book3s_hv.c > > > +++ b/arch/powerpc/kvm/book3s_hv.c > > > @@ -4116,6 +4116,11 @@ static int kvmhv_vcpu_entry_nestedv2(struct kvm_vcpu *vcpu, u64 time_limit, > > > int trap; > > > long rc; > > > > > > + if (vcpu->arch.doorbell_request) { > > > + vcpu->arch.doorbell_request = 0; > > > + kvmppc_set_dpdes(vcpu, 1); > > > + } > > > > This probably looks okay... hmm, is the v1 KVM emulating doorbells > > correctly for SMT L2 guests? I wonder if doorbell emulation isn't > > broken there too because the L1 code looks to be passing in vc->dpdes > > but all the POWER9 emulation code uses doorbell_request. > > > > Yes launching SMT L2 on V1 API fails with a kernel Oops, I'll see if I > can fix that as well. Okay then I didn't miss something. Thanks v1 fix would be good too. I think it should look something like putting doorbell_request into hv_guest_state->dpdes that make the H_ENTER_NESTED call with. For v1 you will need to restore the state back from dpdes back to doorbell_request on exit, because the L0 doesn't keep it for you. Thanks, Nick
diff --git a/Documentation/arch/powerpc/kvm-nested.rst b/Documentation/arch/powerpc/kvm-nested.rst index 630602a8aa00..5defd13cc6c1 100644 --- a/Documentation/arch/powerpc/kvm-nested.rst +++ b/Documentation/arch/powerpc/kvm-nested.rst @@ -546,7 +546,9 @@ table information. +--------+-------+----+--------+----------------------------------+ | 0x1052 | 0x08 | RW | T | CTRL | +--------+-------+----+--------+----------------------------------+ -| 0x1053-| | | | Reserved | +| 0x1053 | 0x08 | RW | T | DPDES | ++--------+-------+----+--------+----------------------------------+ +| 0x1054-| | | | Reserved | | 0x1FFF | | | | | +--------+-------+----+--------+----------------------------------+ | 0x2000 | 0x04 | RW | T | CR | diff --git a/arch/powerpc/include/asm/guest-state-buffer.h b/arch/powerpc/include/asm/guest-state-buffer.h index 808149f31576..d107abe1468f 100644 --- a/arch/powerpc/include/asm/guest-state-buffer.h +++ b/arch/powerpc/include/asm/guest-state-buffer.h @@ -81,6 +81,7 @@ #define KVMPPC_GSID_HASHKEYR 0x1050 #define KVMPPC_GSID_HASHPKEYR 0x1051 #define KVMPPC_GSID_CTRL 0x1052 +#define KVMPPC_GSID_DPDES 0x1053 #define KVMPPC_GSID_CR 0x2000 #define KVMPPC_GSID_PIDR 0x2001 @@ -110,7 +111,7 @@ #define KVMPPC_GSE_META_COUNT (KVMPPC_GSE_META_END - KVMPPC_GSE_META_START + 1) #define KVMPPC_GSE_DW_REGS_START KVMPPC_GSID_GPR(0) -#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_CTRL +#define KVMPPC_GSE_DW_REGS_END KVMPPC_GSID_DPDES #define KVMPPC_GSE_DW_REGS_COUNT \ (KVMPPC_GSE_DW_REGS_END - KVMPPC_GSE_DW_REGS_START + 1) diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index 3e1e2a698c9e..10618622d7ef 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -594,6 +594,7 @@ static inline u##size kvmppc_get_##reg(struct kvm_vcpu *vcpu) \ KVMPPC_BOOK3S_VCORE_ACCESSOR(vtb, 64, KVMPPC_GSID_VTB) +KVMPPC_BOOK3S_VCORE_ACCESSOR(dpdes, 64, KVMPPC_GSID_DPDES) KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(arch_compat, 32, KVMPPC_GSID_LOGICAL_PVR) KVMPPC_BOOK3S_VCORE_ACCESSOR_GET(lpcr, 64, KVMPPC_GSID_LPCR) KVMPPC_BOOK3S_VCORE_ACCESSOR_SET(tb_offset, 64, KVMPPC_GSID_TB_OFFSET) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 35cb014a0c51..cf285e5153ba 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4116,6 +4116,11 @@ static int kvmhv_vcpu_entry_nestedv2(struct kvm_vcpu *vcpu, u64 time_limit, int trap; long rc; + if (vcpu->arch.doorbell_request) { + vcpu->arch.doorbell_request = 0; + kvmppc_set_dpdes(vcpu, 1); + } + io = &vcpu->arch.nestedv2_io; msr = mfmsr(); @@ -4278,9 +4283,16 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, if (kvmhv_on_pseries()) { if (kvmhv_is_nestedv1()) trap = kvmhv_vcpu_entry_p9_nested(vcpu, time_limit, lpcr, tb); - else + else { trap = kvmhv_vcpu_entry_nestedv2(vcpu, time_limit, lpcr, tb); + /* Remember doorbell if it is pending */ + if (kvmppc_get_dpdes(vcpu)) { + vcpu->arch.doorbell_request = 1; + kvmppc_set_dpdes(vcpu, 0); + } + } + /* H_CEDE has to be handled now, not later */ if (trap == BOOK3S_INTERRUPT_SYSCALL && !nested && kvmppc_get_gpr(vcpu, 3) == H_CEDE) { diff --git a/arch/powerpc/kvm/book3s_hv_nestedv2.c b/arch/powerpc/kvm/book3s_hv_nestedv2.c index 8e6f5355f08b..36863fff2a99 100644 --- a/arch/powerpc/kvm/book3s_hv_nestedv2.c +++ b/arch/powerpc/kvm/book3s_hv_nestedv2.c @@ -311,6 +311,10 @@ static int gs_msg_ops_vcpu_fill_info(struct kvmppc_gs_buff *gsb, rc = kvmppc_gse_put_u64(gsb, iden, vcpu->arch.vcore->vtb); break; + case KVMPPC_GSID_DPDES: + rc = kvmppc_gse_put_u64(gsb, iden, + vcpu->arch.vcore->dpdes); + break; case KVMPPC_GSID_LPCR: rc = kvmppc_gse_put_u64(gsb, iden, vcpu->arch.vcore->lpcr); @@ -543,6 +547,9 @@ static int gs_msg_ops_vcpu_refresh_info(struct kvmppc_gs_msg *gsm, case KVMPPC_GSID_VTB: vcpu->arch.vcore->vtb = kvmppc_gse_get_u64(gse); break; + case KVMPPC_GSID_DPDES: + vcpu->arch.vcore->dpdes = kvmppc_gse_get_u64(gse); + break; case KVMPPC_GSID_LPCR: vcpu->arch.vcore->lpcr = kvmppc_gse_get_u64(gse); break; diff --git a/arch/powerpc/kvm/test-guest-state-buffer.c b/arch/powerpc/kvm/test-guest-state-buffer.c index 4720b8dc8837..91ae660cfe21 100644 --- a/arch/powerpc/kvm/test-guest-state-buffer.c +++ b/arch/powerpc/kvm/test-guest-state-buffer.c @@ -151,7 +151,7 @@ static void test_gs_bitmap(struct kunit *test) i++; } - for (u16 iden = KVMPPC_GSID_GPR(0); iden <= KVMPPC_GSID_CTRL; iden++) { + for (u16 iden = KVMPPC_GSID_GPR(0); iden <= KVMPPC_GSID_DPDES; iden++) { kvmppc_gsbm_set(&gsbm, iden); kvmppc_gsbm_set(&gsbm1, iden); KUNIT_EXPECT_TRUE(test, kvmppc_gsbm_test(&gsbm, iden));
Doorbell emulation is broken for KVM on PowerVM guests as support for DPDES was not added in the initial patch series. Due to this, a KVM on PowerVM guest cannot be booted with the XICS interrupt controller as doorbells are to be setup in the initial probe path when using XICS (pSeries_smp_probe()). Add DPDES support in the host KVM code to fix doorbell emulation. Fixes: 6ccbbc33f06a ("KVM: PPC: Add helper library for Guest State Buffers") Cc: stable@vger.kernel.org Signed-off-by: Gautam Menghani <gautam@linux.ibm.com> --- v1 -> v1 resend: 1. Add the stable tag Documentation/arch/powerpc/kvm-nested.rst | 4 +++- arch/powerpc/include/asm/guest-state-buffer.h | 3 ++- arch/powerpc/include/asm/kvm_book3s.h | 1 + arch/powerpc/kvm/book3s_hv.c | 14 +++++++++++++- arch/powerpc/kvm/book3s_hv_nestedv2.c | 7 +++++++ arch/powerpc/kvm/test-guest-state-buffer.c | 2 +- 6 files changed, 27 insertions(+), 4 deletions(-)