The following commit has been merged into the x86/tdx branch of tip: Commit-ID: 752d13305c78b2f0f0d783132f94acc9ce93d38e Gitweb: https://git.kernel.org/tip/752d13305c78b2f0f0d783132f94acc9ce93d38e Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> AuthorDate: Fri, 27 Jan 2023 01:11:56 +03:00 Committer: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> CommitterDate: Fri, 27 Jan 2023 09:42:09 -08:00 x86/tdx: Expand __tdx_hypercall() to handle more arguments So far __tdx_hypercall() only handles six arguments for VMCALL. Expanding it to six more register would allow to cover more use-cases like ReportFatalError() and Hyper-V hypercalls. With all preparations in place, the expansion is pretty straight forward. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/all/20230126221159.8635-5-kirill.shutemov%40linux.intel.com --- arch/x86/coco/tdx/tdcall.S | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-) diff --git a/arch/x86/coco/tdx/tdcall.S b/arch/x86/coco/tdx/tdcall.S index a9bb4cb..5da06d1 100644 --- a/arch/x86/coco/tdx/tdcall.S +++ b/arch/x86/coco/tdx/tdcall.S @@ -13,6 +13,12 @@ /* * Bitmasks of exposed registers (with VMM). */ +#define TDX_RDX BIT(2) +#define TDX_RBX BIT(3) +#define TDX_RSI BIT(6) +#define TDX_RDI BIT(7) +#define TDX_R8 BIT(8) +#define TDX_R9 BIT(9) #define TDX_R10 BIT(10) #define TDX_R11 BIT(11) #define TDX_R12 BIT(12) @@ -27,9 +33,9 @@ * details can be found in TDX GHCI specification, section * titled "TDCALL [TDG.VP.VMCALL] leaf". */ -#define TDVMCALL_EXPOSE_REGS_MASK ( TDX_R10 | TDX_R11 | \ - TDX_R12 | TDX_R13 | \ - TDX_R14 | TDX_R15 ) +#define TDVMCALL_EXPOSE_REGS_MASK \ + ( TDX_RDX | TDX_RBX | TDX_RSI | TDX_RDI | TDX_R8 | TDX_R9 | \ + TDX_R10 | TDX_R11 | TDX_R12 | TDX_R13 | TDX_R14 | TDX_R15 ) /* * __tdx_module_call() - Used by TDX guests to request services from @@ -124,6 +130,7 @@ SYM_FUNC_START(__tdx_hypercall) push %r14 push %r13 push %r12 + push %rbx push %rbp /* Free RDI and RSI to be used as TDVMCALL arguments */ @@ -131,12 +138,18 @@ SYM_FUNC_START(__tdx_hypercall) movq %rsi, %rbp /* Copy hypercall registers from arg struct: */ + movq TDX_HYPERCALL_r8(%rax), %r8 + movq TDX_HYPERCALL_r9(%rax), %r9 movq TDX_HYPERCALL_r10(%rax), %r10 movq TDX_HYPERCALL_r11(%rax), %r11 movq TDX_HYPERCALL_r12(%rax), %r12 movq TDX_HYPERCALL_r13(%rax), %r13 movq TDX_HYPERCALL_r14(%rax), %r14 movq TDX_HYPERCALL_r15(%rax), %r15 + movq TDX_HYPERCALL_rdi(%rax), %rdi + movq TDX_HYPERCALL_rsi(%rax), %rsi + movq TDX_HYPERCALL_rbx(%rax), %rbx + movq TDX_HYPERCALL_rdx(%rax), %rdx push %rax @@ -178,12 +191,18 @@ SYM_FUNC_START(__tdx_hypercall) testq $TDX_HCALL_HAS_OUTPUT, %rbp jz .Lout + movq %r8, TDX_HYPERCALL_r8(%rax) + movq %r9, TDX_HYPERCALL_r9(%rax) movq %r10, TDX_HYPERCALL_r10(%rax) movq %r11, TDX_HYPERCALL_r11(%rax) movq %r12, TDX_HYPERCALL_r12(%rax) movq %r13, TDX_HYPERCALL_r13(%rax) movq %r14, TDX_HYPERCALL_r14(%rax) movq %r15, TDX_HYPERCALL_r15(%rax) + movq %rdi, TDX_HYPERCALL_rdi(%rax) + movq %rsi, TDX_HYPERCALL_rsi(%rax) + movq %rbx, TDX_HYPERCALL_rbx(%rax) + movq %rdx, TDX_HYPERCALL_rdx(%rax) .Lout: /* TDVMCALL leaf return code is in R10 */ movq %r10, %rax @@ -191,14 +210,20 @@ SYM_FUNC_START(__tdx_hypercall) /* * Zero out registers exposed to the VMM to avoid speculative execution * with VMM-controlled values. This needs to include all registers - * present in TDVMCALL_EXPOSE_REGS_MASK (except R12-R15). R12-R15 - * context will be restored. + * present in TDVMCALL_EXPOSE_REGS_MASK, except RBX, and R12-R15 which + * will be restored. */ + xor %r8d, %r8d + xor %r9d, %r9d xor %r10d, %r10d xor %r11d, %r11d + xor %rdi, %rdi + xor %rsi, %rsi + xor %rdx, %rdx /* Restore callee-saved GPRs as mandated by the x86_64 ABI */ pop %rbp + pop %rbx pop %r12 pop %r13 pop %r14
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