| Message ID | 1492556723-9189-12-git-send-email-tbaicar@codeaurora.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Tue, Apr 18, 2017 at 05:05:23PM -0600, Tyler Baicar wrote: > Currently external aborts are unsupported by the guest abort > handling. Add handling for SEAs so that the host kernel reports > SEAs which occur in the guest kernel. > > When an SEA occurs in the guest kernel, the guest exits and is > routed to kvm_handle_guest_abort(). Prior to this patch, a print > message of an unsupported FSC would be printed and nothing else > would happen. With this patch, the code gets routed to the APEI > handling of SEAs in the host kernel to report the SEA information. > > Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org> > Acked-by: Catalin Marinas <catalin.marinas@arm.com> > Acked-by: Marc Zyngier <marc.zyngier@arm.com> > Acked-by: Christoffer Dall <cdall@linaro.org> ... > diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c > index 582a972..fd11855 100644 > --- a/arch/arm/kvm/mmu.c > +++ b/arch/arm/kvm/mmu.c > @@ -29,6 +29,7 @@ > #include <asm/kvm_asm.h> > #include <asm/kvm_emulate.h> > #include <asm/virt.h> > +#include <asm/system_misc.h> > > #include "trace.h" > > @@ -1418,6 +1419,24 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) > kvm_set_pfn_accessed(pfn); > } > > +static bool is_abort_sea(unsigned long fault_status) { ERROR: open brace '{' following function declarations go on the next line #107: FILE: arch/arm/kvm/mmu.c:1422: +static bool is_abort_sea(unsigned long fault_status) { ... > @@ -611,6 +612,24 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) > }; > > /* > + * Handle Synchronous External Aborts that occur in a guest kernel. > + * > + * The return value will be zero if the SEA was successfully handled > + * and non-zero if there was an error processing the error or there was > + * no error to process. > + */ > +int handle_guest_sea(phys_addr_t addr, unsigned int esr) > +{ > + int ret = -ENOENT; > + > + if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) { > + ret = ghes_notify_sea(); > + } WARNING: braces {} are not necessary for single statement blocks #239: FILE: arch/arm64/mm/fault.c:625: + if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) { + ret = ghes_notify_sea(); + } > + > + return ret; > +} > + > +/* > * Dispatch a data abort to the relevant handler. > */ > asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index 612deb3..d286248 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -812,17 +812,18 @@ static int ghes_notify_sci(struct notifier_block *this, > #ifdef CONFIG_ACPI_APEI_SEA > static LIST_HEAD(ghes_sea); > > -void ghes_notify_sea(void) > +int ghes_notify_sea(void) > { > struct ghes *ghes; > + int ret = -ENOENT; > > - /* > - * synchronize_rcu() will wait for nmi_exit(), so no need to > - * rcu_read_lock(). > - */ > + rcu_read_lock(); > list_for_each_entry_rcu(ghes, &ghes_sea, list) { > - ghes_proc(ghes); > + if(!ghes_proc(ghes)) > + ret = 0; What is the idea here: the first time ghes_proc() returns 0, ret is set to 0 and all errors after it will be practically ignored. Looks like it needs more love. Also: ERROR: space required before the open parenthesis '(' #271: FILE: drivers/acpi/apei/ghes.c:822: + if(!ghes_proc(ghes)) Please integrate scripts/checkpatch.pl in your patch creation workflow. Some of the warnings/errors *actually* make sense.
On 5/8/2017 11:40 AM, Borislav Petkov wrote: > On Tue, Apr 18, 2017 at 05:05:23PM -0600, Tyler Baicar wrote: >> Currently external aborts are unsupported by the guest abort >> handling. Add handling for SEAs so that the host kernel reports >> SEAs which occur in the guest kernel. >> >> When an SEA occurs in the guest kernel, the guest exits and is >> routed to kvm_handle_guest_abort(). Prior to this patch, a print >> message of an unsupported FSC would be printed and nothing else >> would happen. With this patch, the code gets routed to the APEI >> handling of SEAs in the host kernel to report the SEA information. >> >> Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org> >> Acked-by: Catalin Marinas <catalin.marinas@arm.com> >> Acked-by: Marc Zyngier <marc.zyngier@arm.com> >> Acked-by: Christoffer Dall <cdall@linaro.org> ... >> + >> + return ret; >> +} >> + >> +/* >> * Dispatch a data abort to the relevant handler. >> */ >> asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, >> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c >> index 612deb3..d286248 100644 >> --- a/drivers/acpi/apei/ghes.c >> +++ b/drivers/acpi/apei/ghes.c >> @@ -812,17 +812,18 @@ static int ghes_notify_sci(struct notifier_block *this, >> #ifdef CONFIG_ACPI_APEI_SEA >> static LIST_HEAD(ghes_sea); >> >> -void ghes_notify_sea(void) >> +int ghes_notify_sea(void) >> { >> struct ghes *ghes; >> + int ret = -ENOENT; >> >> - /* >> - * synchronize_rcu() will wait for nmi_exit(), so no need to >> - * rcu_read_lock(). >> - */ >> + rcu_read_lock(); >> list_for_each_entry_rcu(ghes, &ghes_sea, list) { >> - ghes_proc(ghes); >> + if(!ghes_proc(ghes)) >> + ret = 0; > What is the idea here: the first time ghes_proc() returns 0, ret is set > to 0 and all errors after it will be practically ignored. Looks like it > needs more love. This was discussed in the v12 and v13 patch series. There is existing code in kvm_handle_guest_abort for injecting an abort back into the guest. We only want to do that if it was an abort that was not handled by the firmware first handling. So here we verify that at least one of the SEA error sources successfully reported an error record sent from the firmware. If there were no errors reported by firmware, then we want to continue with the current implementation that will inject the virtual abort. (kvm_inject_vabt) Thanks, Tyler
On Mon, May 08, 2017 at 01:54:44PM -0600, Baicar, Tyler wrote: > This was discussed in the v12 and v13 patch series. There is existing > code in kvm_handle_guest_abort for injecting an abort back into the > guest. We only want to do that if it was an abort that was not handled > by the firmware first handling. So here we verify that at least one of > the SEA error sources successfully reported an error record sent from > the firmware. If there were no errors reported by firmware, then we > want to continue with the current implementation that will inject the > virtual abort. (kvm_inject_vabt) So this needs to be in a comment there. This is generic code in the sense that it is in drivers/acpi/ and it should say why it is doing that special thing. I know, SEA is ARM-only, as far as I'm gathering from reviewing this, but this behavior needs to be documented as it is not obvious. Thanks.
diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index a3f0b3d..ebf020b 100644 --- a/arch/arm/include/asm/kvm_arm.h +++ b/arch/arm/include/asm/kvm_arm.h @@ -187,6 +187,16 @@ #define FSC_FAULT (0x04) #define FSC_ACCESS (0x08) #define FSC_PERM (0x0c) +#define FSC_SEA (0x10) +#define FSC_SEA_TTW0 (0x14) +#define FSC_SEA_TTW1 (0x15) +#define FSC_SEA_TTW2 (0x16) +#define FSC_SEA_TTW3 (0x17) +#define FSC_SECC (0x18) +#define FSC_SECC_TTW0 (0x1c) +#define FSC_SECC_TTW1 (0x1d) +#define FSC_SECC_TTW2 (0x1e) +#define FSC_SECC_TTW3 (0x1f) /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */ #define HPFAR_MASK (~0xf) diff --git a/arch/arm/include/asm/system_misc.h b/arch/arm/include/asm/system_misc.h index a3d61ad..8c4a89f 100644 --- a/arch/arm/include/asm/system_misc.h +++ b/arch/arm/include/asm/system_misc.h @@ -22,6 +22,11 @@ extern unsigned int user_debug; +static inline int handle_guest_sea(phys_addr_t addr, unsigned int esr) +{ + return -1; +} + #endif /* !__ASSEMBLY__ */ #endif /* __ASM_ARM_SYSTEM_MISC_H */ diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 582a972..fd11855 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -29,6 +29,7 @@ #include <asm/kvm_asm.h> #include <asm/kvm_emulate.h> #include <asm/virt.h> +#include <asm/system_misc.h> #include "trace.h" @@ -1418,6 +1419,24 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) kvm_set_pfn_accessed(pfn); } +static bool is_abort_sea(unsigned long fault_status) { + switch (fault_status) { + case FSC_SEA: + case FSC_SEA_TTW0: + case FSC_SEA_TTW1: + case FSC_SEA_TTW2: + case FSC_SEA_TTW3: + case FSC_SECC: + case FSC_SECC_TTW0: + case FSC_SECC_TTW1: + case FSC_SECC_TTW2: + case FSC_SECC_TTW3: + return true; + default: + return false; + } +} + /** * kvm_handle_guest_abort - handles all 2nd stage aborts * @vcpu: the VCPU pointer @@ -1440,19 +1459,29 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) gfn_t gfn; int ret, idx; + fault_status = kvm_vcpu_trap_get_fault_type(vcpu); + + fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); + + /* + * The host kernel will handle the synchronous external abort. There + * is no need to pass the error into the guest. + */ + if (is_abort_sea(fault_status)) { + if (!handle_guest_sea(fault_ipa, kvm_vcpu_get_hsr(vcpu))) + return 1; + } + is_iabt = kvm_vcpu_trap_is_iabt(vcpu); if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) { kvm_inject_vabt(vcpu); return 1; } - fault_ipa = kvm_vcpu_get_fault_ipa(vcpu); - trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu), kvm_vcpu_get_hfar(vcpu), fault_ipa); /* Check the stage-2 fault is trans. fault or write fault */ - fault_status = kvm_vcpu_trap_get_fault_type(vcpu); if (fault_status != FSC_FAULT && fault_status != FSC_PERM && fault_status != FSC_ACCESS) { kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n", diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 6e99978..61d694c 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -204,6 +204,16 @@ #define FSC_FAULT ESR_ELx_FSC_FAULT #define FSC_ACCESS ESR_ELx_FSC_ACCESS #define FSC_PERM ESR_ELx_FSC_PERM +#define FSC_SEA ESR_ELx_FSC_EXTABT +#define FSC_SEA_TTW0 (0x14) +#define FSC_SEA_TTW1 (0x15) +#define FSC_SEA_TTW2 (0x16) +#define FSC_SEA_TTW3 (0x17) +#define FSC_SECC (0x18) +#define FSC_SECC_TTW0 (0x1c) +#define FSC_SECC_TTW1 (0x1d) +#define FSC_SECC_TTW2 (0x1e) +#define FSC_SECC_TTW3 (0x1f) /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */ #define HPFAR_MASK (~UL(0xf)) diff --git a/arch/arm64/include/asm/system_misc.h b/arch/arm64/include/asm/system_misc.h index bc81243..95aa442 100644 --- a/arch/arm64/include/asm/system_misc.h +++ b/arch/arm64/include/asm/system_misc.h @@ -56,6 +56,8 @@ void hook_debug_fault_code(int nr, int (*fn)(unsigned long, unsigned int, __show_ratelimited; \ }) +int handle_guest_sea(phys_addr_t addr, unsigned int esr); + #endif /* __ASSEMBLY__ */ #endif /* __ASM_SYSTEM_MISC_H */ diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 10013ff..a8c5d11 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -515,6 +515,7 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) { struct siginfo info; const struct fault_info *inf; + int ret = 0; inf = esr_to_fault_info(esr); pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n", @@ -527,7 +528,7 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) */ if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) { nmi_enter(); - ghes_notify_sea(); + ret = ghes_notify_sea(); nmi_exit(); } @@ -540,7 +541,7 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) info.si_addr = (void __user *)addr; arm64_notify_die("", regs, &info, esr); - return 0; + return ret; } static const struct fault_info fault_info[] = { @@ -611,6 +612,24 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) }; /* + * Handle Synchronous External Aborts that occur in a guest kernel. + * + * The return value will be zero if the SEA was successfully handled + * and non-zero if there was an error processing the error or there was + * no error to process. + */ +int handle_guest_sea(phys_addr_t addr, unsigned int esr) +{ + int ret = -ENOENT; + + if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) { + ret = ghes_notify_sea(); + } + + return ret; +} + +/* * Dispatch a data abort to the relevant handler. */ asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 612deb3..d286248 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -812,17 +812,18 @@ static int ghes_notify_sci(struct notifier_block *this, #ifdef CONFIG_ACPI_APEI_SEA static LIST_HEAD(ghes_sea); -void ghes_notify_sea(void) +int ghes_notify_sea(void) { struct ghes *ghes; + int ret = -ENOENT; - /* - * synchronize_rcu() will wait for nmi_exit(), so no need to - * rcu_read_lock(). - */ + rcu_read_lock(); list_for_each_entry_rcu(ghes, &ghes_sea, list) { - ghes_proc(ghes); + if(!ghes_proc(ghes)) + ret = 0; } + rcu_read_unlock(); + return ret; } static void ghes_sea_add(struct ghes *ghes) diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h index ef0040893..09e0b65 100644 --- a/include/acpi/ghes.h +++ b/include/acpi/ghes.h @@ -99,6 +99,6 @@ static inline void *acpi_hest_get_payload(struct acpi_hest_generic_data *gdata) return gdata + 1; } -void ghes_notify_sea(void); +int ghes_notify_sea(void); #endif /* GHES_H */