[PATCH v2 0/2] KVM: PPC: Book3S PR: Fixes for AIL and SCV

[PATCH v2 0/2] KVM: PPC: Book3S PR: Fixes for AIL and SCV

[Nicholas Piggin]

The first patch in this series fixes a KVM PR host crash due to a
guest executing the scv instruction or with a pseries SMP host, the
host CPUs executing the scv instruction while a PR guest is running.

The second patch fixes unimplemented H_SET_MODE AIL modes by returning
failure from the hcall rather than succeeding but not implementing
the required behaviour. This works around missing host scv support for
scv-capable Linux guests by causing them to disable the facility.

Still looking at doing a proper capability for QEMU/KVM so we can get
consistency between HV, PR, and TCG. That shouldn't change these
patches though.

Thanks,
Nick

Nicholas Piggin (2):
  KVM: PPC: Book3S PR: Disable SCV when AIL could be disabled
  KVM: PPC: Book3S PR: Disallow AIL != 0

 arch/powerpc/kernel/exceptions-64s.S |  4 ++++
 arch/powerpc/kernel/setup_64.c       | 28 ++++++++++++++++++++++++++++
 arch/powerpc/kvm/Kconfig             |  9 +++++++++
 arch/powerpc/kvm/book3s_pr.c         | 20 ++++++++++++++------
 arch/powerpc/kvm/book3s_pr_papr.c    | 20 ++++++++++++++++++++
 5 files changed, 75 insertions(+), 6 deletions(-)

-- 
2.23.0

[PATCH v2 1/2] KVM: PPC: Book3S PR: Disable SCV when AIL could be disabled

[Nicholas Piggin]

PR KVM does not support running with AIL enabled, and SCV does is not
supported with AIL disabled. Fix this by ensuring the SCV facility is
disabled with FSCR while a CPU could be running with AIL=0.

The PowerNV host supports disabling AIL on a per-CPU basis, so SCV just
needs to be disabled when a vCPU is being run.

The pSeries machine can only switch AIL on a system-wide basis, so it
must disable SCV support at boot if the configuration can potentially
run a PR KVM guest.

Also ensure a the FSCR[SCV] bit can not be enabled when emulating
mtFSCR for the guest.

SCV is not emulated for the PR guest at the moment, this just fixes the
host crashes.

Alternatives considered and rejected:
- SCV support can not be disabled by PR KVM after boot, because it is
  advertised to userspace with HWCAP.
- AIL can not be disabled on a per-CPU basis. At least when running on
  pseries it is a per-LPAR setting.
- Support for real-mode SCV vectors will not be added because they are
  at 0x17000 so making such a large fixed head space causes immediate
  value limits to be exceeded, requiring a lot rework and more code.
- Disabling SCV for any PR KVM possible kernel will cause a slowdown
  when not using PR KVM.
- A boot time option to disable SCV to use PR KVM is user-hostile.
- System call instruction emulation for SCV facility unavailable
  instructions is too complex and old emulation code was subtly broken
  and removed.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S |  4 ++++
 arch/powerpc/kernel/setup_64.c       | 28 ++++++++++++++++++++++++++++
 arch/powerpc/kvm/Kconfig             |  9 +++++++++
 arch/powerpc/kvm/book3s_pr.c         | 20 ++++++++++++++------
 4 files changed, 55 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 55caeee37c08..b66dd6f775a4 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -809,6 +809,10 @@ __start_interrupts:
  * - MSR_EE|MSR_RI is clear (no reentrant exceptions)
  * - Standard kernel environment is set up (stack, paca, etc)
  *
+ * KVM:
+ * These interrupts do not elevate HV 0->1, so HV is not involved. PR KVM
+ * ensures that FSCR[SCV] is disabled whenever it has to force AIL off.
+ *
  * Call convention:
  *
  * syscall register convention is in Documentation/powerpc/syscall64-abi.rst
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index be8577ac9397..7f7da641e551 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -197,6 +197,34 @@ static void __init configure_exceptions(void)
 
 	/* Under a PAPR hypervisor, we need hypercalls */
 	if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
+		/*
+		 * - PR KVM does not support AIL mode interrupts in the host
+		 *   while a PR guest is running.
+		 *
+		 * - SCV system call interrupt vectors are only implemented for
+		 *   AIL mode interrupts.
+		 *
+		 * - On pseries, AIL mode can only be enabled and disabled
+		 *   system-wide so when a PR VM is created on a pseries host,
+		 *   all CPUs of the host are set to AIL=0 mode.
+		 *
+		 * - Therefore host CPUs must not execute scv while a PR VM
+		 *   exists.
+		 *
+		 * - SCV support can not be disabled dynamically because the
+		 *   feature is advertised to host userspace. Disabling the
+		 *   facility and emulating it would be possible but is not
+		 *   implemented.
+		 *
+		 * - So SCV support is blanket diabled if PR KVM could possibly
+		 *   run. That is, PR support compiled in, booting on pseries
+		 *   with hash MMU.
+		 */
+		if (IS_ENABLED(CONFIG_KVM_BOOK3S_PR_POSSIBLE) && !radix_enabled()) {
+			init_task.thread.fscr &= ~FSCR_SCV;
+			cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_SCV;
+		}
+
 		/* Enable AIL if possible */
 		if (!pseries_enable_reloc_on_exc()) {
 			init_task.thread.fscr &= ~FSCR_SCV;
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index 18e58085447c..ddd88179110a 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -112,12 +112,21 @@ config KVM_BOOK3S_64_PR
 	  guest in user mode (problem state) and emulating all
 	  privileged instructions and registers.
 
+	  This is only available for hash MMU mode and only supports
+	  guests that use hash MMU mode.
+
 	  This is not as fast as using hypervisor mode, but works on
 	  machines where hypervisor mode is not available or not usable,
 	  and can emulate processors that are different from the host
 	  processor, including emulating 32-bit processors on a 64-bit
 	  host.
 
+	  Selecting this option will cause the SCV facility to be
+	  disabled when the kernel is booted on the pseries platform in
+	  hash MMU mode (regardless of PR VMs running). When any PR VMs
+	  are running, "AIL" mode is disabled which may slow interrupts
+	  and system calls on the host.
+
 config KVM_BOOK3S_HV_EXIT_TIMING
 	bool "Detailed timing for hypervisor real-mode code"
 	depends on KVM_BOOK3S_HV_POSSIBLE && DEBUG_FS
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 34a801c3604a..4d1c84b94b77 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -140,9 +140,12 @@ static void kvmppc_core_vcpu_load_pr(struct kvm_vcpu *vcpu, int cpu)
 #endif
 
 	/* Disable AIL if supported */
-	if (cpu_has_feature(CPU_FTR_HVMODE) &&
-	    cpu_has_feature(CPU_FTR_ARCH_207S))
-		mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~LPCR_AIL);
+	if (cpu_has_feature(CPU_FTR_HVMODE)) {
+		if (cpu_has_feature(CPU_FTR_ARCH_207S))
+			mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~LPCR_AIL);
+		if (cpu_has_feature(CPU_FTR_ARCH_300) && (current->thread.fscr & FSCR_SCV))
+			mtspr(SPRN_FSCR, mfspr(SPRN_FSCR) & ~FSCR_SCV);
+	}
 
 	vcpu->cpu = smp_processor_id();
 #ifdef CONFIG_PPC_BOOK3S_32
@@ -175,9 +178,12 @@ static void kvmppc_core_vcpu_put_pr(struct kvm_vcpu *vcpu)
 	kvmppc_save_tm_pr(vcpu);
 
 	/* Enable AIL if supported */
-	if (cpu_has_feature(CPU_FTR_HVMODE) &&
-	    cpu_has_feature(CPU_FTR_ARCH_207S))
-		mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_AIL_3);
+	if (cpu_has_feature(CPU_FTR_HVMODE)) {
+		if (cpu_has_feature(CPU_FTR_ARCH_207S))
+			mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_AIL_3);
+		if (cpu_has_feature(CPU_FTR_ARCH_300) && (current->thread.fscr & FSCR_SCV))
+			mtspr(SPRN_FSCR, mfspr(SPRN_FSCR) | FSCR_SCV);
+	}
 
 	vcpu->cpu = -1;
 }
@@ -1037,6 +1043,8 @@ static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac)
 
 void kvmppc_set_fscr(struct kvm_vcpu *vcpu, u64 fscr)
 {
+	if (fscr & FSCR_SCV)
+		fscr &= ~FSCR_SCV; /* SCV must not be enabled */
 	if ((vcpu->arch.fscr & FSCR_TAR) && !(fscr & FSCR_TAR)) {
 		/* TAR got dropped, drop it in shadow too */
 		kvmppc_giveup_fac(vcpu, FSCR_TAR_LG);
-- 
2.23.0

[PATCH v2 2/2] KVM: PPC: Book3S PR: Disallow AIL != 0

[Nicholas Piggin]

KVM PR does not implement address translation modes on interrupt, so it
must not allow H_SET_MODE to succeed. The behaviour change caused by
this mode is architected and not advisory (interrupts *must* behave
differently).

QEMU does not deal with differences in AIL support in the host. The
solution to that is a spapr capability and corresponding KVM CAP, but
this patch does not break things more than before (the host behaviour
already differs, this change just disallows some modes that are not
implemented properly).

By happy coincidence, this allows PR Linux guests that are using the SCV
facility to boot and run, because Linux disables the use of SCV if AIL
can not be set to 3. This does not fix the underlying problem of missing
SCV support (an OS could implement real-mode SCV vectors and try to
enable the facility). The true fix for that is for KVM PR to emulate scv
interrupts from the facility unavailable interrupt.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_pr_papr.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c
index 1f10e7dfcdd0..dc4f51ac84bc 100644
--- a/arch/powerpc/kvm/book3s_pr_papr.c
+++ b/arch/powerpc/kvm/book3s_pr_papr.c
@@ -281,6 +281,22 @@ static int kvmppc_h_pr_logical_ci_store(struct kvm_vcpu *vcpu)
 	return EMULATE_DONE;
 }
 
+static int kvmppc_h_pr_set_mode(struct kvm_vcpu *vcpu)
+{
+	unsigned long mflags = kvmppc_get_gpr(vcpu, 4);
+	unsigned long resource = kvmppc_get_gpr(vcpu, 5);
+
+	if (resource == H_SET_MODE_RESOURCE_ADDR_TRANS_MODE) {
+		/* KVM PR does not provide AIL!=0 to guests */
+		if (mflags == 0)
+			kvmppc_set_gpr(vcpu, 3, H_SUCCESS);
+		else
+			kvmppc_set_gpr(vcpu, 3, H_UNSUPPORTED_FLAG_START - 63);
+		return EMULATE_DONE;
+	}
+	return EMULATE_FAIL;
+}
+
 #ifdef CONFIG_SPAPR_TCE_IOMMU
 static int kvmppc_h_pr_put_tce(struct kvm_vcpu *vcpu)
 {
@@ -384,6 +400,8 @@ int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
 		return kvmppc_h_pr_logical_ci_load(vcpu);
 	case H_LOGICAL_CI_STORE:
 		return kvmppc_h_pr_logical_ci_store(vcpu);
+	case H_SET_MODE:
+		return kvmppc_h_pr_set_mode(vcpu);
 	case H_XIRR:
 	case H_CPPR:
 	case H_EOI:
@@ -421,6 +439,7 @@ int kvmppc_hcall_impl_pr(unsigned long cmd)
 	case H_CEDE:
 	case H_LOGICAL_CI_LOAD:
 	case H_LOGICAL_CI_STORE:
+	case H_SET_MODE:
 #ifdef CONFIG_KVM_XICS
 	case H_XIRR:
 	case H_CPPR:
@@ -447,6 +466,7 @@ static unsigned int default_hcall_list[] = {
 	H_BULK_REMOVE,
 	H_PUT_TCE,
 	H_CEDE,
+	H_SET_MODE,
 #ifdef CONFIG_KVM_XICS
 	H_XIRR,
 	H_CPPR,
-- 
2.23.0

Re: [PATCH v2 2/2] KVM: PPC: Book3S PR: Disallow AIL != 0

[Fabiano Rosas]

Nicholas Piggin <npiggin@gmail.com> writes:

> KVM PR does not implement address translation modes on interrupt, so it
> must not allow H_SET_MODE to succeed. The behaviour change caused by
> this mode is architected and not advisory (interrupts *must* behave
> differently).
>
> QEMU does not deal with differences in AIL support in the host. The
> solution to that is a spapr capability and corresponding KVM CAP, but
> this patch does not break things more than before (the host behaviour
> already differs, this change just disallows some modes that are not
> implemented properly).
>
> By happy coincidence, this allows PR Linux guests that are using the SCV
> facility to boot and run, because Linux disables the use of SCV if AIL
> can not be set to 3. This does not fix the underlying problem of missing
> SCV support (an OS could implement real-mode SCV vectors and try to
> enable the facility). The true fix for that is for KVM PR to emulate scv
> interrupts from the facility unavailable interrupt.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

> ---
>  arch/powerpc/kvm/book3s_pr_papr.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>
> diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c
> index 1f10e7dfcdd0..dc4f51ac84bc 100644
> --- a/arch/powerpc/kvm/book3s_pr_papr.c
> +++ b/arch/powerpc/kvm/book3s_pr_papr.c
> @@ -281,6 +281,22 @@ static int kvmppc_h_pr_logical_ci_store(struct kvm_vcpu *vcpu)
>  	return EMULATE_DONE;
>  }
>
> +static int kvmppc_h_pr_set_mode(struct kvm_vcpu *vcpu)
> +{
> +	unsigned long mflags = kvmppc_get_gpr(vcpu, 4);
> +	unsigned long resource = kvmppc_get_gpr(vcpu, 5);
> +
> +	if (resource == H_SET_MODE_RESOURCE_ADDR_TRANS_MODE) {
> +		/* KVM PR does not provide AIL!=0 to guests */
> +		if (mflags == 0)
> +			kvmppc_set_gpr(vcpu, 3, H_SUCCESS);
> +		else
> +			kvmppc_set_gpr(vcpu, 3, H_UNSUPPORTED_FLAG_START - 63);
> +		return EMULATE_DONE;
> +	}
> +	return EMULATE_FAIL;
> +}
> +
>  #ifdef CONFIG_SPAPR_TCE_IOMMU
>  static int kvmppc_h_pr_put_tce(struct kvm_vcpu *vcpu)
>  {
> @@ -384,6 +400,8 @@ int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
>  		return kvmppc_h_pr_logical_ci_load(vcpu);
>  	case H_LOGICAL_CI_STORE:
>  		return kvmppc_h_pr_logical_ci_store(vcpu);
> +	case H_SET_MODE:
> +		return kvmppc_h_pr_set_mode(vcpu);
>  	case H_XIRR:
>  	case H_CPPR:
>  	case H_EOI:
> @@ -421,6 +439,7 @@ int kvmppc_hcall_impl_pr(unsigned long cmd)
>  	case H_CEDE:
>  	case H_LOGICAL_CI_LOAD:
>  	case H_LOGICAL_CI_STORE:
> +	case H_SET_MODE:
>  #ifdef CONFIG_KVM_XICS
>  	case H_XIRR:
>  	case H_CPPR:
> @@ -447,6 +466,7 @@ static unsigned int default_hcall_list[] = {
>  	H_BULK_REMOVE,
>  	H_PUT_TCE,
>  	H_CEDE,
> +	H_SET_MODE,
>  #ifdef CONFIG_KVM_XICS
>  	H_XIRR,
>  	H_CPPR,

Re: [PATCH v2 1/2] KVM: PPC: Book3S PR: Disable SCV when AIL could be disabled

[Fabiano Rosas]

Nicholas Piggin <npiggin@gmail.com> writes:

> PR KVM does not support running with AIL enabled, and SCV does is not
> supported with AIL disabled. Fix this by ensuring the SCV facility is
> disabled with FSCR while a CPU could be running with AIL=0.
>
> The PowerNV host supports disabling AIL on a per-CPU basis, so SCV just
> needs to be disabled when a vCPU is being run.
>
> The pSeries machine can only switch AIL on a system-wide basis, so it
> must disable SCV support at boot if the configuration can potentially
> run a PR KVM guest.
>
> Also ensure a the FSCR[SCV] bit can not be enabled when emulating
> mtFSCR for the guest.
>
> SCV is not emulated for the PR guest at the moment, this just fixes the
> host crashes.
>
> Alternatives considered and rejected:
> - SCV support can not be disabled by PR KVM after boot, because it is
>   advertised to userspace with HWCAP.
> - AIL can not be disabled on a per-CPU basis. At least when running on
>   pseries it is a per-LPAR setting.
> - Support for real-mode SCV vectors will not be added because they are
>   at 0x17000 so making such a large fixed head space causes immediate
>   value limits to be exceeded, requiring a lot rework and more code.
> - Disabling SCV for any PR KVM possible kernel will cause a slowdown
>   when not using PR KVM.
> - A boot time option to disable SCV to use PR KVM is user-hostile.
> - System call instruction emulation for SCV facility unavailable
>   instructions is too complex and old emulation code was subtly broken
>   and removed.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  arch/powerpc/kernel/exceptions-64s.S |  4 ++++
>  arch/powerpc/kernel/setup_64.c       | 28 ++++++++++++++++++++++++++++
>  arch/powerpc/kvm/Kconfig             |  9 +++++++++
>  arch/powerpc/kvm/book3s_pr.c         | 20 ++++++++++++++------
>  4 files changed, 55 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index 55caeee37c08..b66dd6f775a4 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -809,6 +809,10 @@ __start_interrupts:
>   * - MSR_EE|MSR_RI is clear (no reentrant exceptions)
>   * - Standard kernel environment is set up (stack, paca, etc)
>   *
> + * KVM:
> + * These interrupts do not elevate HV 0->1, so HV is not involved. PR KVM
> + * ensures that FSCR[SCV] is disabled whenever it has to force AIL off.
> + *
>   * Call convention:
>   *
>   * syscall register convention is in Documentation/powerpc/syscall64-abi.rst
> diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
> index be8577ac9397..7f7da641e551 100644
> --- a/arch/powerpc/kernel/setup_64.c
> +++ b/arch/powerpc/kernel/setup_64.c
> @@ -197,6 +197,34 @@ static void __init configure_exceptions(void)
>
>  	/* Under a PAPR hypervisor, we need hypercalls */
>  	if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
> +		/*
> +		 * - PR KVM does not support AIL mode interrupts in the host
> +		 *   while a PR guest is running.
> +		 *
> +		 * - SCV system call interrupt vectors are only implemented for
> +		 *   AIL mode interrupts.
> +		 *
> +		 * - On pseries, AIL mode can only be enabled and disabled
> +		 *   system-wide so when a PR VM is created on a pseries host,
> +		 *   all CPUs of the host are set to AIL=0 mode.
> +		 *
> +		 * - Therefore host CPUs must not execute scv while a PR VM
> +		 *   exists.
> +		 *
> +		 * - SCV support can not be disabled dynamically because the
> +		 *   feature is advertised to host userspace. Disabling the
> +		 *   facility and emulating it would be possible but is not
> +		 *   implemented.
> +		 *
> +		 * - So SCV support is blanket diabled if PR KVM could possibly

disabled

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

Re: [PATCH v2 1/2] KVM: PPC: Book3S PR: Disable SCV when AIL could be disabled

[kernel test robot]

Hi Nicholas,

I love your patch! Yet something to improve:

[auto build test ERROR on powerpc/topic/ppc-kvm]
[also build test ERROR on powerpc/next v5.17-rc2 next-20220202]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Nicholas-Piggin/KVM-PPC-Book3S-PR-Fixes-for-AIL-and-SCV/20220129-152655
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git topic/ppc-kvm
config: powerpc-randconfig-r005-20220131 (https://download.01.org/0day-ci/archive/20220202/202202022141.phJ3zWBF-lkp@intel.com/config)
compiler: powerpc-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/a751cf4de8f5854152b969afed947b0640ab0c33
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Nicholas-Piggin/KVM-PPC-Book3S-PR-Fixes-for-AIL-and-SCV/20220129-152655
        git checkout a751cf4de8f5854152b969afed947b0640ab0c33
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/kvm/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   arch/powerpc/kvm/book3s_pr.c: In function 'kvmppc_core_vcpu_load_pr':
>> arch/powerpc/kvm/book3s_pr.c:146:74: error: 'struct thread_struct' has no member named 'fscr'
     146 |                 if (cpu_has_feature(CPU_FTR_ARCH_300) && (current->thread.fscr & FSCR_SCV))
         |                                                                          ^
   arch/powerpc/kvm/book3s_pr.c: In function 'kvmppc_core_vcpu_put_pr':
   arch/powerpc/kvm/book3s_pr.c:184:74: error: 'struct thread_struct' has no member named 'fscr'
     184 |                 if (cpu_has_feature(CPU_FTR_ARCH_300) && (current->thread.fscr & FSCR_SCV))
         |                                                                          ^


vim +146 arch/powerpc/kvm/book3s_pr.c

   141	
   142		/* Disable AIL if supported */
   143		if (cpu_has_feature(CPU_FTR_HVMODE)) {
   144			if (cpu_has_feature(CPU_FTR_ARCH_207S))
   145				mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~LPCR_AIL);
 > 146			if (cpu_has_feature(CPU_FTR_ARCH_300) && (current->thread.fscr & FSCR_SCV))
   147				mtspr(SPRN_FSCR, mfspr(SPRN_FSCR) & ~FSCR_SCV);
   148		}
   149	
   150		vcpu->cpu = smp_processor_id();
   151	#ifdef CONFIG_PPC_BOOK3S_32
   152		current->thread.kvm_shadow_vcpu = vcpu->arch.shadow_vcpu;
   153	#endif
   154	
   155		if (kvmppc_is_split_real(vcpu))
   156			kvmppc_fixup_split_real(vcpu);
   157	
   158		kvmppc_restore_tm_pr(vcpu);
   159	}
   160	

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0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

Re: [PATCH v2 1/2] KVM: PPC: Book3S PR: Disable SCV when AIL could be disabled

[kernel test robot]

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Hi Nicholas,

I love your patch! Yet something to improve:

[auto build test ERROR on powerpc/topic/ppc-kvm]
[also build test ERROR on powerpc/next v5.17-rc2 next-20220202]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Nicholas-Piggin/KVM-PPC-Book3S-PR-Fixes-for-AIL-and-SCV/20220129-152655
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git topic/ppc-kvm
config: powerpc-randconfig-r005-20220131 (https://download.01.org/0day-ci/archive/20220202/202202022141.phJ3zWBF-lkp(a)intel.com/config)
compiler: powerpc-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/a751cf4de8f5854152b969afed947b0640ab0c33
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Nicholas-Piggin/KVM-PPC-Book3S-PR-Fixes-for-AIL-and-SCV/20220129-152655
        git checkout a751cf4de8f5854152b969afed947b0640ab0c33
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/kvm/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   arch/powerpc/kvm/book3s_pr.c: In function 'kvmppc_core_vcpu_load_pr':
>> arch/powerpc/kvm/book3s_pr.c:146:74: error: 'struct thread_struct' has no member named 'fscr'
     146 |                 if (cpu_has_feature(CPU_FTR_ARCH_300) && (current->thread.fscr & FSCR_SCV))
         |                                                                          ^
   arch/powerpc/kvm/book3s_pr.c: In function 'kvmppc_core_vcpu_put_pr':
   arch/powerpc/kvm/book3s_pr.c:184:74: error: 'struct thread_struct' has no member named 'fscr'
     184 |                 if (cpu_has_feature(CPU_FTR_ARCH_300) && (current->thread.fscr & FSCR_SCV))
         |                                                                          ^


vim +146 arch/powerpc/kvm/book3s_pr.c

   141	
   142		/* Disable AIL if supported */
   143		if (cpu_has_feature(CPU_FTR_HVMODE)) {
   144			if (cpu_has_feature(CPU_FTR_ARCH_207S))
   145				mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~LPCR_AIL);
 > 146			if (cpu_has_feature(CPU_FTR_ARCH_300) && (current->thread.fscr & FSCR_SCV))
   147				mtspr(SPRN_FSCR, mfspr(SPRN_FSCR) & ~FSCR_SCV);
   148		}
   149	
   150		vcpu->cpu = smp_processor_id();
   151	#ifdef CONFIG_PPC_BOOK3S_32
   152		current->thread.kvm_shadow_vcpu = vcpu->arch.shadow_vcpu;
   153	#endif
   154	
   155		if (kvmppc_is_split_real(vcpu))
   156			kvmppc_fixup_split_real(vcpu);
   157	
   158		kvmppc_restore_tm_pr(vcpu);
   159	}
   160	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org