| Message ID | a67c877521a6913911bd569c38c772ade6a1403b.1699368322.git.isaku.yamahata@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM TDX basic feature support | expand |
On 11/7/2023 10:55 PM, isaku.yamahata@intel.com wrote: > From: Isaku Yamahata <isaku.yamahata@intel.com> > > Some SEAMCALL may return TDX_RND_NO_ENTROPY error when the entropy is > lacking. Retry SEAMCALL on the error following rdrand_long() to retry > RDRAND_RETRY_LOOPS times. > > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > arch/x86/kvm/vmx/tdx_errno.h | 1 + > arch/x86/kvm/vmx/tdx_ops.h | 40 +++++++++++++++++++++--------------- > 2 files changed, 24 insertions(+), 17 deletions(-) > > diff --git a/arch/x86/kvm/vmx/tdx_errno.h b/arch/x86/kvm/vmx/tdx_errno.h > index 7f96696b8e7c..bb093e292fef 100644 > --- a/arch/x86/kvm/vmx/tdx_errno.h > +++ b/arch/x86/kvm/vmx/tdx_errno.h > @@ -14,6 +14,7 @@ > #define TDX_OPERAND_INVALID 0xC000010000000000ULL > #define TDX_OPERAND_BUSY 0x8000020000000000ULL > #define TDX_PREVIOUS_TLB_EPOCH_BUSY 0x8000020100000000ULL > +#define TDX_RND_NO_ENTROPY 0x8000020300000000ULL > #define TDX_VCPU_NOT_ASSOCIATED 0x8000070200000000ULL > #define TDX_KEY_GENERATION_FAILED 0x8000080000000000ULL > #define TDX_KEY_STATE_INCORRECT 0xC000081100000000ULL > diff --git a/arch/x86/kvm/vmx/tdx_ops.h b/arch/x86/kvm/vmx/tdx_ops.h > index 12fd6b8d49e0..a55977626ae3 100644 > --- a/arch/x86/kvm/vmx/tdx_ops.h > +++ b/arch/x86/kvm/vmx/tdx_ops.h > @@ -6,6 +6,7 @@ > > #include <linux/compiler.h> > > +#include <asm/archrandom.h> > #include <asm/cacheflush.h> > #include <asm/asm.h> > #include <asm/kvm_host.h> > @@ -17,25 +18,30 @@ > static inline u64 tdx_seamcall(u64 op, u64 rcx, u64 rdx, u64 r8, u64 r9, > struct tdx_module_args *out) > { > + int retry; > u64 ret; > > - if (out) { > - *out = (struct tdx_module_args) { > - .rcx = rcx, > - .rdx = rdx, > - .r8 = r8, > - .r9 = r9, > - }; > - ret = __seamcall_ret(op, out); > - } else { > - struct tdx_module_args args = { > - .rcx = rcx, > - .rdx = rdx, > - .r8 = r8, > - .r9 = r9, > - }; > - ret = __seamcall(op, &args); > - } > + /* Mimic the existing rdrand_long() to retry RDRAND_RETRY_LOOPS times. */ > + retry = RDRAND_RETRY_LOOPS; Nit: The value can be assigned when define. Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> > + do { > + if (out) { > + *out = (struct tdx_module_args) { > + .rcx = rcx, > + .rdx = rdx, > + .r8 = r8, > + .r9 = r9, > + }; > + ret = __seamcall_ret(op, out); > + } else { > + struct tdx_module_args args = { > + .rcx = rcx, > + .rdx = rdx, > + .r8 = r8, > + .r9 = r9, > + }; > + ret = __seamcall(op, &args); > + } > + } while (unlikely(ret == TDX_RND_NO_ENTROPY) && --retry); > if (unlikely(ret == TDX_SEAMCALL_UD)) { > /* > * SEAMCALLs fail with TDX_SEAMCALL_UD returned when VMX is off.
On Tue, 2023-11-07 at 06:55 -0800, isaku.yamahata@intel.com wrote: > From: Isaku Yamahata <isaku.yamahata@intel.com> > > Some SEAMCALL may return TDX_RND_NO_ENTROPY error when the entropy is > lacking. Retry SEAMCALL on the error following rdrand_long() to retry > RDRAND_RETRY_LOOPS times. > > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > arch/x86/kvm/vmx/tdx_errno.h | 1 + > arch/x86/kvm/vmx/tdx_ops.h | 40 +++++++++++++++++++++--------------- > 2 files changed, 24 insertions(+), 17 deletions(-) > > diff --git a/arch/x86/kvm/vmx/tdx_errno.h b/arch/x86/kvm/vmx/tdx_errno.h > index 7f96696b8e7c..bb093e292fef 100644 > --- a/arch/x86/kvm/vmx/tdx_errno.h > +++ b/arch/x86/kvm/vmx/tdx_errno.h > @@ -14,6 +14,7 @@ > #define TDX_OPERAND_INVALID 0xC000010000000000ULL > #define TDX_OPERAND_BUSY 0x8000020000000000ULL > #define TDX_PREVIOUS_TLB_EPOCH_BUSY 0x8000020100000000ULL > +#define TDX_RND_NO_ENTROPY 0x8000020300000000ULL > #define TDX_VCPU_NOT_ASSOCIATED 0x8000070200000000ULL > #define TDX_KEY_GENERATION_FAILED 0x8000080000000000ULL > #define TDX_KEY_STATE_INCORRECT 0xC000081100000000ULL > diff --git a/arch/x86/kvm/vmx/tdx_ops.h b/arch/x86/kvm/vmx/tdx_ops.h > index 12fd6b8d49e0..a55977626ae3 100644 > --- a/arch/x86/kvm/vmx/tdx_ops.h > +++ b/arch/x86/kvm/vmx/tdx_ops.h > @@ -6,6 +6,7 @@ > > #include <linux/compiler.h> > > +#include <asm/archrandom.h> > #include <asm/cacheflush.h> > #include <asm/asm.h> > #include <asm/kvm_host.h> > @@ -17,25 +18,30 @@ > static inline u64 tdx_seamcall(u64 op, u64 rcx, u64 rdx, u64 r8, u64 r9, > struct tdx_module_args *out) > { > + int retry; > u64 ret; > > - if (out) { > - *out = (struct tdx_module_args) { > - .rcx = rcx, > - .rdx = rdx, > - .r8 = r8, > - .r9 = r9, > - }; > - ret = __seamcall_ret(op, out); > - } else { > - struct tdx_module_args args = { > - .rcx = rcx, > - .rdx = rdx, > - .r8 = r8, > - .r9 = r9, > - }; > - ret = __seamcall(op, &args); > - } > + /* Mimic the existing rdrand_long() to retry RDRAND_RETRY_LOOPS times. */ > + retry = RDRAND_RETRY_LOOPS; > + do { > + if (out) { > + *out = (struct tdx_module_args) { > + .rcx = rcx, > + .rdx = rdx, > + .r8 = r8, > + .r9 = r9, > + }; > + ret = __seamcall_ret(op, out); > + } else { > + struct tdx_module_args args = { > + .rcx = rcx, > + .rdx = rdx, > + .r8 = r8, > + .r9 = r9, > + }; > + ret = __seamcall(op, &args); > + } > + } while (unlikely(ret == TDX_RND_NO_ENTROPY) && --retry); > if (unlikely(ret == TDX_SEAMCALL_UD)) { > /* > * SEAMCALLs fail with TDX_SEAMCALL_UD returned when VMX is off. Why we cannot use seamcall*() variants directly which already handles running out of entropy error?
diff --git a/arch/x86/kvm/vmx/tdx_errno.h b/arch/x86/kvm/vmx/tdx_errno.h index 7f96696b8e7c..bb093e292fef 100644 --- a/arch/x86/kvm/vmx/tdx_errno.h +++ b/arch/x86/kvm/vmx/tdx_errno.h @@ -14,6 +14,7 @@ #define TDX_OPERAND_INVALID 0xC000010000000000ULL #define TDX_OPERAND_BUSY 0x8000020000000000ULL #define TDX_PREVIOUS_TLB_EPOCH_BUSY 0x8000020100000000ULL +#define TDX_RND_NO_ENTROPY 0x8000020300000000ULL #define TDX_VCPU_NOT_ASSOCIATED 0x8000070200000000ULL #define TDX_KEY_GENERATION_FAILED 0x8000080000000000ULL #define TDX_KEY_STATE_INCORRECT 0xC000081100000000ULL diff --git a/arch/x86/kvm/vmx/tdx_ops.h b/arch/x86/kvm/vmx/tdx_ops.h index 12fd6b8d49e0..a55977626ae3 100644 --- a/arch/x86/kvm/vmx/tdx_ops.h +++ b/arch/x86/kvm/vmx/tdx_ops.h @@ -6,6 +6,7 @@ #include <linux/compiler.h> +#include <asm/archrandom.h> #include <asm/cacheflush.h> #include <asm/asm.h> #include <asm/kvm_host.h> @@ -17,25 +18,30 @@ static inline u64 tdx_seamcall(u64 op, u64 rcx, u64 rdx, u64 r8, u64 r9, struct tdx_module_args *out) { + int retry; u64 ret; - if (out) { - *out = (struct tdx_module_args) { - .rcx = rcx, - .rdx = rdx, - .r8 = r8, - .r9 = r9, - }; - ret = __seamcall_ret(op, out); - } else { - struct tdx_module_args args = { - .rcx = rcx, - .rdx = rdx, - .r8 = r8, - .r9 = r9, - }; - ret = __seamcall(op, &args); - } + /* Mimic the existing rdrand_long() to retry RDRAND_RETRY_LOOPS times. */ + retry = RDRAND_RETRY_LOOPS; + do { + if (out) { + *out = (struct tdx_module_args) { + .rcx = rcx, + .rdx = rdx, + .r8 = r8, + .r9 = r9, + }; + ret = __seamcall_ret(op, out); + } else { + struct tdx_module_args args = { + .rcx = rcx, + .rdx = rdx, + .r8 = r8, + .r9 = r9, + }; + ret = __seamcall(op, &args); + } + } while (unlikely(ret == TDX_RND_NO_ENTROPY) && --retry); if (unlikely(ret == TDX_SEAMCALL_UD)) { /* * SEAMCALLs fail with TDX_SEAMCALL_UD returned when VMX is off.