| Message ID | 20200914172750.852684-4-georgepope@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | UBSan Enablement for hyp/nVHE code | expand |
On Mon, Sep 14, 2020 at 05:27:39PM +0000, George-Aurelian Popescu wrote: > From: George Popescu <georgepope@google.com> > > Share a buffer between the kernel and the hyp/nVHE code by using the > macros from kvm_debug_buffer.h. > > The buffer is composed of a writing index and a statically allocated > array. The writing index counts how many elements have been written inside > the buffer and should be set to zero whenever the code goes back to > EL2 with the clear_kvm_debug_buffer macro. > > To avoid consistency problems the buffer is defined per_cpu and is designed > to be read-only from the kernel perspective. > > Check if there is any logging data from hyp/nVHE code. > > Every time when the state returns back to the kernel after an hvc call, > the __kvm_arm_check_debug_buffer macro checks if there is any data inside > one of the predefined buffers. > > Signed-off-by: George Popescu <georgepope@google.com> > --- > arch/arm64/include/asm/kvm_debug_buffer.h | 34 +++++++++++++++++++++++ > arch/arm64/include/asm/kvm_host.h | 6 ++++ > arch/arm64/kvm/hyp/hyp-entry.S | 2 +- > 3 files changed, 41 insertions(+), 1 deletion(-) > create mode 100644 arch/arm64/include/asm/kvm_debug_buffer.h > > diff --git a/arch/arm64/include/asm/kvm_debug_buffer.h b/arch/arm64/include/asm/kvm_debug_buffer.h > new file mode 100644 > index 000000000000..30c9b0b1a7bf > --- /dev/null > +++ b/arch/arm64/include/asm/kvm_debug_buffer.h > @@ -0,0 +1,34 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * Copyright 2020 Google LLC > + * Author: George Popescu <georgepope@google.com> > + */ > +#ifndef __ASSEMBLY__ > + > +#include <linux/percpu-defs.h> > +#include <asm/kvm_asm.h> > + > +#ifdef __KVM_NVHE_HYPERVISOR__ > +#define DEFINE_KVM_DEBUG_BUFFER(type_name, buff_name, size) \ > + DEFINE_PER_CPU(type_name, buff_name)[(size)]; \ > + DEFINE_PER_CPU(unsigned long, buff_name##_wr_ind) = 0 > + > +#define DECLARE_KVM_DEBUG_BUFFER(type_name, buff_name, size) \ > + DECLARE_PER_CPU(type_name, buff_name)[(size)]; \ > + DECLARE_PER_CPU(unsigned long, buff_name##_wr_ind) > + > +#else > + > +#define DECLARE_KVM_DEBUG_BUFFER(type_name, buff_name, size) \ > + DECLARE_PER_CPU(type_name, kvm_nvhe_sym(buff_name))[(size)]; \ > + DECLARE_PER_CPU(unsigned long, kvm_nvhe_sym(buff_name##_wr_ind)) > +#endif //__KVM_NVHE_HYPERVISOR__ nit: comment style, here and below > + > +#else > + > +.macro clear_kvm_debug_buffer sym tmp1, tmp2, tmp3 > + mov \tmp1, 0 > + hyp_str_this_cpu \sym, \tmp1, \tmp2, \tmp3 > +.endm Can you can use xzr (zero register) directly rather than moving the constant 0 into a temporary? hyp_str_this_cpu \sym, xzr, \tmp1, \tmp2 > + > +#endif // __ASSEMBLY__ > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 905c2b87e05a..adc8957e9321 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -494,6 +494,10 @@ u64 __kvm_call_hyp(void *hypfn, ...); > __kvm_call_hyp(kvm_ksym_ref_nvhe(f), ##__VA_ARGS__); \ > }) > > +#define __kvm_arm_check_debug_buffer() \ > +{ \ > +} > + > /* > * The couple of isb() below are there to guarantee the same behaviour > * on VHE as on !VHE, where the eret to EL1 acts as a context > @@ -506,6 +510,7 @@ u64 __kvm_call_hyp(void *hypfn, ...); > isb(); \ > } else { \ > kvm_call_hyp_nvhe(f, ##__VA_ARGS__); \ > + __kvm_arm_check_debug_buffer(); \ > } \ > } while(0) > > @@ -518,6 +523,7 @@ u64 __kvm_call_hyp(void *hypfn, ...); > isb(); \ > } else { \ > ret = kvm_call_hyp_nvhe_ret(f, ##__VA_ARGS__); \ > + __kvm_arm_check_debug_buffer(); \ As Will was pointing out earlier, does the checking need to have preemption disabled in case there is another call into hyp that corrupts the buffer while it is being checked? > } \ > \ > ret; \ > diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S > index 46b4dab933d0..8df0082b9ccf 100644 > --- a/arch/arm64/kvm/hyp/hyp-entry.S > +++ b/arch/arm64/kvm/hyp/hyp-entry.S > @@ -68,7 +68,7 @@ el1_sync: // Guest trapped into EL2 > cbnz x1, el1_hvc_guest // called HVC > > /* Here, we're pretty sure the host called HVC. */ > - ldp x0, x1, [sp], #16 > + ldp x0, x1, [sp], #16 Is this a whitespace change? Maybe drop from this patch if it isn't related. > > /* Check for a stub HVC call */ > cmp x0, #HVC_STUB_HCALL_NR > -- > 2.28.0.618.gf4bc123cb7-goog >
diff --git a/arch/arm64/include/asm/kvm_debug_buffer.h b/arch/arm64/include/asm/kvm_debug_buffer.h new file mode 100644 index 000000000000..30c9b0b1a7bf --- /dev/null +++ b/arch/arm64/include/asm/kvm_debug_buffer.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2020 Google LLC + * Author: George Popescu <georgepope@google.com> + */ +#ifndef __ASSEMBLY__ + +#include <linux/percpu-defs.h> +#include <asm/kvm_asm.h> + +#ifdef __KVM_NVHE_HYPERVISOR__ +#define DEFINE_KVM_DEBUG_BUFFER(type_name, buff_name, size) \ + DEFINE_PER_CPU(type_name, buff_name)[(size)]; \ + DEFINE_PER_CPU(unsigned long, buff_name##_wr_ind) = 0 + +#define DECLARE_KVM_DEBUG_BUFFER(type_name, buff_name, size) \ + DECLARE_PER_CPU(type_name, buff_name)[(size)]; \ + DECLARE_PER_CPU(unsigned long, buff_name##_wr_ind) + +#else + +#define DECLARE_KVM_DEBUG_BUFFER(type_name, buff_name, size) \ + DECLARE_PER_CPU(type_name, kvm_nvhe_sym(buff_name))[(size)]; \ + DECLARE_PER_CPU(unsigned long, kvm_nvhe_sym(buff_name##_wr_ind)) +#endif //__KVM_NVHE_HYPERVISOR__ + +#else + +.macro clear_kvm_debug_buffer sym tmp1, tmp2, tmp3 + mov \tmp1, 0 + hyp_str_this_cpu \sym, \tmp1, \tmp2, \tmp3 +.endm + +#endif // __ASSEMBLY__ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 905c2b87e05a..adc8957e9321 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -494,6 +494,10 @@ u64 __kvm_call_hyp(void *hypfn, ...); __kvm_call_hyp(kvm_ksym_ref_nvhe(f), ##__VA_ARGS__); \ }) +#define __kvm_arm_check_debug_buffer() \ +{ \ +} + /* * The couple of isb() below are there to guarantee the same behaviour * on VHE as on !VHE, where the eret to EL1 acts as a context @@ -506,6 +510,7 @@ u64 __kvm_call_hyp(void *hypfn, ...); isb(); \ } else { \ kvm_call_hyp_nvhe(f, ##__VA_ARGS__); \ + __kvm_arm_check_debug_buffer(); \ } \ } while(0) @@ -518,6 +523,7 @@ u64 __kvm_call_hyp(void *hypfn, ...); isb(); \ } else { \ ret = kvm_call_hyp_nvhe_ret(f, ##__VA_ARGS__); \ + __kvm_arm_check_debug_buffer(); \ } \ \ ret; \ diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 46b4dab933d0..8df0082b9ccf 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -68,7 +68,7 @@ el1_sync: // Guest trapped into EL2 cbnz x1, el1_hvc_guest // called HVC /* Here, we're pretty sure the host called HVC. */ - ldp x0, x1, [sp], #16 + ldp x0, x1, [sp], #16 /* Check for a stub HVC call */ cmp x0, #HVC_STUB_HCALL_NR