From b9b4fe3a72b60c8d74a9ffb61aa778f04eaddd87 Mon Sep 17 00:00:00 2001 From: Dexuan Cui Date: Thu, 24 Aug 2023 01:07:10 -0700 Subject: x86/hyperv: Use TDX GHCI to access some MSRs in a TDX VM with the paravisor When the paravisor is present, a SNP VM must use GHCB to access some special MSRs, including HV_X64_MSR_GUEST_OS_ID and some SynIC MSRs. Similarly, when the paravisor is present, a TDX VM must use TDX GHCI to access the same MSRs. Implement hv_tdx_msr_write() and hv_tdx_msr_read(), and use the helper functions hv_ivm_msr_read() and hv_ivm_msr_write() to access the MSRs in a unified way for SNP/TDX VMs with the paravisor. Do not export hv_tdx_msr_write() and hv_tdx_msr_read(), because we never really used hv_ghcb_msr_write() and hv_ghcb_msr_read() in any module. Update arch/x86/include/asm/mshyperv.h so that the kernel can still build if CONFIG_AMD_MEM_ENCRYPT or CONFIG_INTEL_TDX_GUEST is not set, or neither is set. Signed-off-by: Dexuan Cui Reviewed-by: Tianyu Lan Reviewed-by: Michael Kelley Signed-off-by: Wei Liu Link: https://lore.kernel.org/r/20230824080712.30327-9-decui@microsoft.com --- arch/x86/kernel/cpu/mshyperv.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/x86/kernel/cpu') diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 4c5a174935ca..4f51dac9eeb2 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -70,8 +70,8 @@ u64 hv_get_non_nested_register(unsigned int reg) { u64 value; - if (hv_is_synic_reg(reg) && hv_isolation_type_snp()) - hv_ghcb_msr_read(reg, &value); + if (hv_is_synic_reg(reg) && ms_hyperv.paravisor_present) + hv_ivm_msr_read(reg, &value); else rdmsrl(reg, value); return value; @@ -80,8 +80,8 @@ EXPORT_SYMBOL_GPL(hv_get_non_nested_register); void hv_set_non_nested_register(unsigned int reg, u64 value) { - if (hv_is_synic_reg(reg) && hv_isolation_type_snp()) { - hv_ghcb_msr_write(reg, value); + if (hv_is_synic_reg(reg) && ms_hyperv.paravisor_present) { + hv_ivm_msr_write(reg, value); /* Write proxy bit via wrmsl instruction */ if (hv_is_sint_reg(reg)) -- cgit v1.2.3